Marie Demetriou KC

Ranked in 6 Practice Areas

Star Individuals

Competition Law

London (Bar)

19 Years Ranked

Star Individuals

European Law

London (Bar)

19 Years Ranked

Band 2

Administrative & Public Law

London (Bar)

19 Years Ranked

Band 2

Group Litigation

All Circuits

3 Years Ranked

Band 3

Civil Liberties & Human Rights

London (Bar)

15 Years Ranked

Band 4

Sport

London (Bar)

1 Years Ranked

Ranked in Guides

Global 2025

About

Provided by Marie Demetriou KC

UK Bar

Practice Areas

Marie Demetriou KC is widely recognised as a leading advocate in the fields of competition law, EU law, public law and human rights, and is increasingly sought after for her advocacy skills in a broad range of commercial, regulatory and enforcement matters, particularly in the appellate Courts. In 2019-20 Marie won both the Chambers & Partners Competition Silk of the Year and the Legal 500 EU and Competition Silk of the Year awards and was also one of 12 barristers to be named as one of The Lawyer’s Hot 100 2020. Marie is also Star Rated for competition law in the Chambers & Partners directory. Since 2015 Marie has been Standing Counsel to the Competition and Markets Authority, representing the CMA in its major litigation in the courts. Between 2016 and 2018 Marie was Chair of the Bar European Group.

Chambers Review

Provided by Chambers

UK Bar

Competition Law - London (Bar)

Star Individuals

Individual Editorial

Marie Demetriou KC is routinely involved in the biggest competition cases of the day and receives stellar feedback from an array of sources. She is standing counsel to the CMA and has experience in key appeals against the regulator's decisions. She also advises on both sides of cartel damages claims and has appeared on behalf of proposed class representatives for claimant groups.

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European Law - London (Bar)

Star Individuals

Individual Editorial

Marie Demetriou KC is a highly acclaimed stellar practitioner who advises clients on EU asylum rights as well as representing them in a number of European law judicial review challenges. She also has a leading competition and state aid practice, in addition to regularly assisting clients with jurisdictional matters.

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Administrative & Public Law - London (Bar)

Band 2

Individual Editorial

Marie Demetriou KC commands great respect for her expertise in public law cases involving provisions of EU law. She also handles cases concerning human rights, immigration and asylum, and social security provisions. She receives instructions from corporates, as well as regulators.

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Group Litigation - All Circuits

Band 2

Individual Editorial

Marie Demetriou KC is a hugely impressive competition-specialist silk with a vast knowledge of precedent-setting work in collective actions, including certification matters.

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Civil Liberties & Human Rights - London (Bar)

Band 3

Individual Editorial

Marie Demetriou KC is an esteemed silk demonstrating core strength in areas of human rights such as political protest, immigration and torture. She is typically seen assisting claimants and interveners, regularly representing the UNHCR in important asylum rights cases.

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Sport - London (Bar)

Band 4

Individual Editorial

Marie Demetriou KC is noted for her robust sports practice, which sees her instructed on competition law matters, arbitrations and commercial disputes. She is frequently called upon to act in matters involving a variety of sports, including football, golf and Formula 1.

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Strengths

Provided by Chambers

She is a delight to work with and a really good advocate, very clear and persuasive in court. It's not surprising she's one of the top competition lawyers in the UK.

Competition Law respondent
UK Bar

Marie's advocacy is just next level. I've never seen anybody command a courtroom like that; judges are hanging on her every word. Everything she says is imbued with an extra level of authority.

Competition Law respondent
UK Bar

Marie is not just one of the leading figures at the competition Bar, but a leading figure, full stop. A fantastic advocate, very streetwise in terms of spotting the winning point and executing it.

Competition Law respondent
UK Bar

I couldn't put it highly enough to say she is not just one of my favourite people but probably my number one silk to work with. She is incredibly bright, not just in competition but also public law.

Competition Law respondent
UK Bar

Marie could charm the birds from the trees. She has a really smooth, really easygoing advocacy style that doesn't wind up the tribunal ever - it's magical to see. She's tremendous.

Competition Law respondent
UK Bar

She is one of the best in her generation, now one of the top EU and public lawyers. She is an incredibly effective advocate and also a completely lovely person to work with.

European Law respondent
UK Bar

Marie is a super star, she's absolutely phenomenal.

European Law respondent
UK Bar

She is a delight to work with and a really good advocate, very clear and persuasive in court.

European Law respondent
UK Bar

Marie is an absolutely top-class advocate.

European Law respondent
UK Bar

I think very highly of her. She is very good on her feet; well structured, calm and persuasive. She is an excellent advocate.

European Law respondent
UK Bar

Marie is a real go-to for public law issues.

Administrative & Public Law respondent
UK Bar

Marie is very astute and very good at handling difficult problems.

Administrative & Public Law respondent
UK Bar

She has an in-depth understanding of public law and is a top-notch cross-examiner. Marie is a powerful advocate and works at incredible pace under any amount of pressure.

Administrative & Public Law respondent
UK Bar

Her advocacy, she would charm the birds from the trees. She has a really smooth and easy-going advocacy style, its magical to see. She's tremendous.

Group Litigation respondent
UK Bar

Marie is a fantastic, a brilliant advocate, and she is also a pleasure to work with.

Group Litigation respondent
UK Bar

She is exceptionally talented and brilliant.

Group Litigation respondent
UK Bar

Marie is an absolute superstar.

Civil Liberties & Human Rights respondent
UK Bar

Marie is brilliant.

Civil Liberties & Human Rights respondent
UK Bar

Marie's advocacy was amongst the best I have seen.

Civil Liberties & Human Rights respondent
UK Bar

Marie is brilliantly sharp, an exceptional advocate and an absolute pleasure to work with.

Civil Liberties & Human Rights respondent
UK Bar

Marie is very strong all round.

Civil Liberties & Human Rights respondent
UK Bar

Marie is highly intelligent and an excellent advocate.

Sport respondent
UK Bar

Marie's drafting is crisp and powerful, she motivates juniors and builds strong teams, and you always feel that she is available and on your side. Her client-handling skills are excellent.

Sport respondent
UK Bar

In addition to being technically excellent, she has a strategic mind and understands the room and the playing field.

Sport respondent
UK Bar

She is a delight to work with and a really good advocate, very clear and persuasive in court. It's not surprising she's one of the top competition lawyers in the UK.

Competition Law respondent
UK Bar

Marie's advocacy is just next level. I've never seen anybody command a courtroom like that; judges are hanging on her every word. Everything she says is imbued with an extra level of authority.

Competition Law respondent
UK Bar

Marie is not just one of the leading figures at the competition Bar, but a leading figure, full stop. A fantastic advocate, very streetwise in terms of spotting the winning point and executing it.

Competition Law respondent
UK Bar

I couldn't put it highly enough to say she is not just one of my favourite people but probably my number one silk to work with. She is incredibly bright, not just in competition but also public law.

Competition Law respondent
UK Bar

Marie could charm the birds from the trees. She has a really smooth, really easygoing advocacy style that doesn't wind up the tribunal ever - it's magical to see. She's tremendous.

Competition Law respondent
UK Bar

She is one of the best in her generation, now one of the top EU and public lawyers. She is an incredibly effective advocate and also a completely lovely person to work with.

European Law respondent
UK Bar

Marie is a super star, she's absolutely phenomenal.

European Law respondent
UK Bar

She is a delight to work with and a really good advocate, very clear and persuasive in court.

European Law respondent
UK Bar

Marie is an absolutely top-class advocate.

European Law respondent
UK Bar

I think very highly of her. She is very good on her feet; well structured, calm and persuasive. She is an excellent advocate.

European Law respondent
UK Bar

Marie is a real go-to for public law issues.

Administrative & Public Law respondent
UK Bar

Marie is very astute and very good at handling difficult problems.

Administrative & Public Law respondent
UK Bar

She has an in-depth understanding of public law and is a top-notch cross-examiner. Marie is a powerful advocate and works at incredible pace under any amount of pressure.

Administrative & Public Law respondent
UK Bar

Her advocacy, she would charm the birds from the trees. She has a really smooth and easy-going advocacy style, its magical to see. She's tremendous.

Group Litigation respondent
UK Bar

Marie is a fantastic, a brilliant advocate, and she is also a pleasure to work with.

Group Litigation respondent
UK Bar

She is exceptionally talented and brilliant.

Group Litigation respondent
UK Bar

Marie is an absolute superstar.

Civil Liberties & Human Rights respondent
UK Bar

Marie is brilliant.

Civil Liberties & Human Rights respondent
UK Bar

Marie's advocacy was amongst the best I have seen.

Civil Liberties & Human Rights respondent
UK Bar

Marie is brilliantly sharp, an exceptional advocate and an absolute pleasure to work with.

Civil Liberties & Human Rights respondent
UK Bar

Marie is very strong all round.

Civil Liberties & Human Rights respondent
UK Bar

Marie is highly intelligent and an excellent advocate.

Sport respondent
UK Bar

Marie's drafting is crisp and powerful, she motivates juniors and builds strong teams, and you always feel that she is available and on your side. Her client-handling skills are excellent.

Sport respondent
UK Bar

In addition to being technically excellent, she has a strategic mind and understands the room and the playing field.

Sport respondent
UK Bar

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