Gary Oliver
Senior Clerk
+44 (0) 207 822 7325
Daniel’s practice focuses on commercial, public & regulatory, competition and sports law. Daniel has particular experience in the intersection of public and commercial law. He is regularly instructed in commercial judicial reviews, and brought into other high-stake litigation requiring public, commercial and/or competition law expertise.
Daniel is ranked in the directories for public law work (Legal 500 and Chambers & Partners), commercial work (Chambers & Partners) and telecommunications (Legal 500, Chambers & Partners).
Daniel frequently acts both against and for the Government and he is a member of the Attorney General's B panel. He has an established practice in the regulatory field, where he has acted for and/or against regulators in the fields of telecommunications, competition, financial services, legal services, water, energy, sports and aviation.
Recent highlights of Daniel’s practice include:
Daniel accepts instructions in all areas of public law, and he has substantial judicial review experience. He was appointed to the Attorney General's B Panel Counsel with effect from 1 September 2023.
Daniel is ranked by the Legal 500 (2025) and Chambers and Partners (2025) for Administrative and Public Law.
Daniel also acts on regulatory and professional discipline matters. He has acted for and/or against regulators in the fields of finance, competition, energy, telecommunications, water, legal services, sports and aviation. He has gained significant experience in the field of energy regulation, having spent four months in 2015-16 on secondment to Ofgem, and has acted regularly in energy-related disputes thereafter.
“Daniel is phenomenally bright and quick to get to grips with massive complex factual and legal complications. The speed of his uptake is extraordinary and his advocacy is superb.”
Chambers and Partners, 2025
“Daniel goes out of his way to respond even when busy, providing targeted and valuable advice.”
Chambers and Partners, 2025
“He is an excellent drafter, very responsive and conscientious.”
Chambers and Partners, 2025
“A junior who listens and is firm in his advice.”
Legal 500, 2025
“He is very efficient; really on it, in terms of understanding the issues, and really easy to work with.”
Chambers and Partners, 2023
“He has an excellent understanding of public law and how it applies to public bodies and conveys complex matters with simplicity and focus.”
Chambers and Partners, 2023
“Daniel is very approachable and technically and procedurally excellent. He quickly gets to grips with clients' commercial environments and their impact upon the case at hand.”
Chambers and Partners, 2023
“Exceptionally bright and hard working. Super responsive – an absolute star junior in the public law space.”
Legal 500, 2023
“He is the best public law junior at his level by a distance.”
Legal 500, 2021
“He is right up there with the strongest public law barristers.”
Chambers and Partners, 2022
“He grasps complex matters very efficiently and is an absolutely stellar performer.”
Chambers and Partners, 2022
“Highly responsive and client-focused.”
Chambers and Partners, 2022
“A clear and effective advocate.”
Chambers and Partners, 2022
“His paperwork is barely edited by the best silks and he works quickly and well in large teams.”
Legal 500, 2021
“Very bright, works quickly and well. Always adds value and combines seamlessly with solicitors.”
Legal 500, 2021
“He has an unusual clarity of thought and expression and is thoroughly clever to work with.”
Legal 500, 2021
Daniel is acting as junior counsel for Claimants/Complainants in the IPT, concerning the legality of a targeted equipment interference warrant under the Investigatory Powers Act 2016.
Daniel was junior counsel for the Claimant in this tax challenge concerning legitimate expectations.
Daniel was junior counsel for the Claimant in this judicial review challenge to a determination of the Financial Ombudsman in the context of timeshare contracts.
Daniel was junior counsel for the Secretary of State in this commercial judicial review concerning enfranchisement of the Ministry of Defence's Service Family Accommodation.
Acting variously for the FCA, PRA, and for regulated individuals and financial institutions, in the context of contested regulatory proceedings.
Daniel was junior counsel in this judicial review of the UKSA's and Chancellor's decision to replace RPI with CPIH from 2030.
Daniel was junior counsel in this judicial review to a decision of the Investigatory Powers Tribunal.
Daniel is acting as junior counsel for Camelot in its procurement challenge to the award of the fourth National Lottery licence.
Daniel acted as sole counsel for the Claimant in this judicial review considering the amenability to review of Code bodies in the context of the micro generation certification scheme.
Acting as junior Counsel for the Minister in relation to a challenge to the arrangements for blind and partially-sighted persons to vote without assistance at the general election in December 2019
Acting for GEMA before the CMA in relation to challenges to the RIIO2 price control.
Junior Counsel for the Medical Protection Society in this challenge to the scheme for GP indemnities. Daniel appeared as sole counsel in interlocutory matters.
The Divisional Court has dismissed a challenge to the temporary cessation of jury trials due to the coronavirus pandemic. Daniel acted for the Lord Chancellor and the Lord Chief Justice.
The three airlines challenged the UK 14 day quarantine regulations. The airlines claimed that the regulations were irrational and disproportionate. Daniel acted on behalf of the airlines.
Acted on behalf of Hutchison 3G UK Limited. The Court of Appeal dismissed Ofcom’s appeal against a judgment of the High Court awarding over £218 million plus interest as restitution of unjust enrichment to four Mobile Network Operators.
The Court of Appeal upheld the High Court’s dismissal of a challenge to the ban on dealing in ivory imposed by the Ivory Act 2018. Daniel acted for the Respondent Secretary of State.
Acting for the Civil Aviation Authority in internal regulatory proceedings and in a judicial review in relation to matters arising from the administration of Thomas Cook and the EU aviation regime.
The Supreme Court concluded that the Prime Minister’s advice to her Majesty was unlawful, void or of no effect and Gina Miller’s appeal was allowed and the Advocate General’s appeal in the case of Cherry is dismissed. Daniel was instructed by the Public Law Project.
Acting for the Claimant in a State Aid challenge to the capacity market (as junior to Tristan Jones).
Acting for the Authority in a judicial review of a decision concerning regulated revenue made pursuant to the Offshore Transmission Licence.
Acting for the interested party, Camelot, (as junior to Dinah Rose QC) in this judicial review concerning the regulation of betting on the EuroMillions lottery.
Acting for Ofgem before the Authority's Enforcement Decision Panel in a contested case concerning installation of Advanced Meters. The Authority imposed a penalty of £2.4m on npower. (As junior to Javan Herberg QC).
Acting for the Claimant in a judicial review of Ofcom's decision relating to 5G spectrum auction caps, both at first instance and on appeal to the Court of Appeal.
Acting for the Civil Aviation Authority in successful proceedings to remove Monarch Airlines' operating licence and air operator certificate (as junior to Alan Maclean QC).
Acting as junior Counsel for Ofcom in a six-week hearing in the CAT, in which BT challenged Ofcom's market definition exercise in its business connectivity market review.
Daniel was junior counsel for Privacy International against the Security and Intelligence Agencies. The long-running case was heard in the Investigatory Powers Tribunal, Court of Justice, and (on an application for judicial review) the Divisional Court.
Acting for an individual in the first re-referral to the Tribunal of a decision by the FCA, appealing the individual’s prohibition of a significant influence function. The Tribunal agreed (contrary to the FCA’s submission) that it was permitted to consider the facts de novo, even in a second referral (as junior to Andrew George QC).
Daniel accepts instructions in all areas of commercial litigation, and frequently acts both as sole counsel and as part of a wider team. He regularly appears in the Business and Property Courts (Commercial / Chancery) and in arbitrations, covering a wide variety of commercial disputes.
“Daniel Cashman knew absolutely everything about the sprawling case in question and consistently came up with helpful and no-fuss solutions to problems.”
Chambers and Partners, 2025
“He is an outstanding lawyer and an excellent advocate. He's also very personable and good at gaining the confidence of professional and lay clients alike.”
Chambers and Partners, 2025
Daniel was junior counsel for the defendant, successfully defending this claim valued at over £1 billion. The claimant claimed relief under an alleged oral trust, alternatively in promissory estoppel. The action was dismissed in its entirety, and the defendant awarded indemnity costs.
Acting as junior for a multi-week trial in the Commercial Court.
Previously, acting in an application for service out of the jurisdiction and resisting a stay on grounds of forum non conveniens. The High Court granted the Claimants’ application and agreed that there should not be a stay on grounds of forum non conveniens.
Daniel acted as junior counsel for the Defendant in this application concerning whether there was jurisdiction to bring a counterclaim in the High Court in the context of an arbitration claim for enforcement of a New York Convention award .
Daniel acted for five directors in defence of allegations that they acted in breach of duties under the Companies Act 2006.
Counsel for the executive producer of a feature film in a contractual dispute, in which the executive producer succeeded.
Acted on behalf of Hutchison 3G UK Limited. The Court of Appeal dismissed Ofcom’s appeal against a judgment of the High Court awarding over £218 million plus interest as restitution of unjust enrichment to four Mobile Network Operators.
Application to set aside a freezing injunction.
A claim for serious irregularity under section 68 of the Arbitration Act 1996, arising out of a high-value LCIA arbitration.
Acting (as junior to Adam Baradon) for six claimants in claims for fraudulent misrepresentation, breach of trust, breach of fiduciary duty, breach of contract and other grounds in respect of 10 investment schemes, amounting to approximately £15 million. Obtaining freezing orders including under the Chabra jurisdiction against 14 respondent parties, together with ancillary relief including a passport order and orders for alternative service.
Acting for the Claimant in a commercial contractual dispute related to the online payment and gambling sectors. The High Court found in favour of the Claimant in respect of all issues before it.
Acting for the Appellant (as junior to Michael Beloff QC and Stephen Nathan QC) in this case considering the legal test for permission to serve out of the jurisdiction and for implication of terms as to interest.
Acting for the Claimants in a claim alleging breach of FSA/FCA rules in selling index-linked notes (as junior to Ian Mill QC). The Claimants were awarded damages of $23.6m.
Acting as sole counsel for the Claimants in a commercial dispute relating to the sale and purchase of six restaurants.
Acting for a commercial finance company in this dispute concerning the enforcement of a confidentiality and non-circumvent agreement (as junior to Andrew George QC).
Acting as sole counsel for the Defendant in the Commercial Court, in relation to a multi-million pound claim, for a declaration of stay and opposing an application for default judgment.
Acting in LCIA arbitrations, including as sole counsel in a multi-million dollar commercial dispute, in relation to competition issues in a dispute in the EU air transport sector and in a commercial franchise dispute.
Daniel accepts instructions in all areas of sports law, including regulatory/disciplinary, commercial and competition. He has particular experience in legal issues arising in football, and has acted for numerous football clubs and regulatory bodies.
Acted for both regulators and clubs in sport arbitrations under Rule K of the Football Association Rules and sections 8 and 9 of the EFL Regulations.
Acting for a Championship Football Club in a sporting arbitration relating to the ability of non-parties to bring disciplinary appeals under the EFL Regulations.
Acted for the EFL in a misconduct charge brought by the EFL against Stevenage FC in relation to fixture obligations and/or the obligation to act with the utmost good faith with respect to the postponement of a scheduled League Two game.
Acting for the Claimant in a claim concerning payment pursuant to a franchise agreement in a major overseas sports league (as junior to Andrew George QC).
Acting for Watford Football Club in a contractual dispute
Daniel accepts instructions in all areas of Competition law. He has experience of competition law both from a regulatory perspective and in commercial damages claims.
Daniel is acting for Ofwat (as intervener) in this application for collective proceedings against water companies.
Daniel is junior counsel for the US Closed Banks in this competition damages action concerning LIBOR suppression.
Daniel is a junior for the CMA in this statutory appeal of the CMA's decision finding an anti-competitive agreement in the pharmaceutical sector (prochlorperazine).
Daniel is acting on behalf of various local authority Claimants in relation to a substantial follow-on damages claim arising from the Trucks cartel.
Acting (as junior to Tom de la Mare QC and Tristan Jones) for the proposed class representative in the first opt-out class action in the UK concerning infringements of competition law in the sale of mobility scooters.
Acting in LCIA arbitrations, including as sole counsel in a multi-million dollar commercial dispute, in relation to competition issues in a dispute in the EU air transport sector and in a commercial franchise dispute.
Acting for the Claimant in a State Aid challenge to the capacity market (as junior to Tristan Jones).
Daniel accepts instructions in all areas of EU law, which often overlaps with other areas of his work (competition law, telecommunications, public law).
Acting for the Civil Aviation Authority in internal regulatory proceedings and in a judicial review in relation to matters arising from the administration of Thomas Cook and the EU aviation regime.
Acting for the Claimant in a State Aid challenge to the capacity market (as junior to Tristan Jones).
Acting for the Claimant in a judicial review of Ofcom's decision relating to 5G spectrum auction caps, both at first instance and on appeal to the Court of Appeal.
Acting for the Civil Aviation Authority in successful proceedings to remove Monarch Airlines' operating licence and air operator certificate (as junior to Alan Maclean QC).
Acting as junior Counsel for Ofcom in a six-week hearing in the CAT, in which BT challenged Ofcom's market definition exercise in its business connectivity market review.
Various advice to a telecommunications provider in the UK and elsewhere in the EU, including in relation to spectrum trading and net neutrality.
Daniel accepts instructions in all areas of Civil Liberties & Human Rights law. He has substantial recent experience of human rights matters arising in the Administrative Court and Investigatory Powers Tribunal.
Daniel is acting as junior counsel for Claimants/Complainants in the IPT, concerning the legality of a targeted equipment interference warrant under the Investigatory Powers Act 2016.
Daniel was junior counsel, acting pro bono for the Claimants in a challenge to MI5's holding of data, pursuant to ECHR and EU law. The Tribunal found that MI5 and the Secretary of State had acted unlawfully.
Daniel was junior counsel in this judicial review to a decision of the Investigatory Powers Tribunal.
Acting for the Lord Chancellor in a case considering the suitability of summary judgment/strike out in the context of claims under the Human Rights Act 1998. Daniel was sole counsel in the successful appeal in the King's Bench Division.
Daniel was junior counsel for Privacy International against the Security and Intelligence Agencies. The long-running case was heard in the Investigatory Powers Tribunal, Court of Justice, and (on an application for judicial review) the Divisional Court.
MA (Oxon) Jurisprudence (Law with German Law): First Class; BPTC (Kaplan): Outstanding; BCL (Oxon): Distinction
2018, 2019, 2020: Cashman, Ratan & Scott, The British Yearbook of International Law, Decisions of British Courts involving questions of private international law
VAT registration number: 218074420
Barristers regulated by the Bar Standards Board
Gary Oliver
Senior Clerk
+44 (0) 207 822 7325
Derek Sutton
Deputy Senior Clerk
+44 (0) 207 822 7327
Adam Sloane
Deputy Senior Clerk
+44 (0) 207 822 7326
Dean Tolman
Clerk
+44 (0) 207 822 7331
Billy Brian
Clerk
+44 (0) 207 822 7339
Marc Armstrong
Clerk
+44 (0) 207 822 7330
Adam Fuschillo
Clerk
+44 (0) 207 822 7329
Danny Compton
Clerk
+44 (0) 207 822 7338
Sophie Reeve
Clerk
+44 (0) 207 822 7324
Toby Dennison
Clerk
+44 (0) 207 822 7328
Daniel Higgins
Clerk
+44 (0) 207 822 7322
Lilly-Grace Hilliard
Clerk
+44 (0)20 7822 7234