Follow us

Hannah is a Partner and solicitor advocate in the international arbitration and public international law group.

Hannah advises clients and colleagues globally on complex issues relating to commercial and investment arbitration, dispute resolution, enforcement of awards and judgments, and public international law.

Hannah has acted as counsel in ad hoc commercial arbitrations and proceedings under the auspices of major arbitral institutions, including the ICC, LCIA and SCC. She has acted as counsel on a number of investment treaty claims, and advised clients on investment structuring. She also has experience in advising on a range of other public international law matters, including state immunity, immunity of international organisations, and boundaries. She works across a number of sectors, including energy, mining, pharma and financial institutions and banks.

Hannah is listed as a Next Generation Partner in International Arbitration and Public International Law categories in Legal 500 UK, 2023 and "Up and Coming" in Chambers and Partners 2024 for Public International Law, who state that "Hannah Ambrose is recognised as an up-and-coming practitioner in the field of PIL and investor-state arbitration. She has a breadth of experience assisting clients with international commercial disputes and conflict-related policy advice".

Hannah is a member of the City of London Law Society's International Arbitration Committee.

Hannah is a member of the firm's steering committee for our pro bono international development project, Fair Deal Sierra Leone, and is on the steering group of the UK-Sierra Leone Pro Bono Network.

Hannah is a trustee of The International Lawyers Project, a leading international charity advancing economic justice and the rule of law through provision of pro bono legal expertise to civil society, parliaments and communities.

Experience & expertise

Selected matters

Investment Treaty Arbitration and Public International Law

  • Nord Stream 2 in its claim against the EU under the Energy Charter Treaty (until February 2022)
  • Vedanta Resources PLC on a claim against India under the UK-India Bilateral Investment Treaty arising from the imposition of retroactive tax
  • a Central Asian government and its national oil company in ICSID arbitration proceedings brought against it by UK and Georgia-based investors under a BIT and the ECT in connection with their withdrawal from a major oil field and related contractual issues
  • one of the largest energy producers in Europe on its investment treaty claims under a BIT and the ECT against the Russian Federation
  • a Western European hydrocarbon exploration and production company in a potential claim under a BIT and the Energy Charter Treaty against an Eastern European state
  • an international leasing company regarding international law remedies under investment treaties, WTO treaties, and various other treaties concerning the actions of Russia and other sovereign states further to Russia's invasion of Ukraine and Russia's counter-sanctions, on settlement of an investment treaty claim and on five related LCIA arbitrations
  • an international mining company regarding its rights under investment treaties and the European Convention on Human Rights concerning the threat to its investment arising from Russia's invasion of Ukraine
  • a global integrated energy company on international law issues in relation to the development of a gas field that straddles an international boundary
  • a west African state on a threatened investment treaty claim
  • an international investment bank regarding its rights under international law concerning a threat to its investment in Russia arising from Russia's invasion of Ukraine
  • a number of utility companies and infrastructure funds on investor-State arbitration and investment structuring in a scenario of future nationalisation, including questions as to availability and scope of treaty protections and related quantum issues
  • a pharmaceutical company on protections under investment treaties in respect of anticipated interference with its IP rights
  • a multinational oil and gas company on issues relating to arbitration and the immunity of international organisations in connection with a gas project in West Africa
  • an international financial institution concerning its options under public international law, including international investment, EU and WTO law, for bringing proceedings against a State, including to challenge its exercise of extra-territorial jurisdiction.
  • an oil and gas company on application of international law in UK domestic court proceedings in response to a question raised by the UK Supreme Court
  • an oil and gas company and a Chinese shipping company on application of the EU Blocking Regulation in the context of US sanctions against Iran
  • a social outcomes investor on state immunity, international organisation immunity, dispute resolution and governing law regarding proposed investments in Africa (involving UNICEF, the World Bank and two States)

Commercial Arbitration

  • a West African state in an LCIA arbitration concerning termination of a mining licence
  • a pharmaceutical company in an ICC arbitration in connection with the termination of a supply and distribution agreement in a Middle Eastern country
  • a major Korean bank on the recovery of a substantial investment in a Jersey based derivative-linked securities fund
  • a real estate investment fund in two ICC arbitrations concerning default under a facility agreement and guarantee
  • a multinational chemicals and technology company in a £500m dispute and threatened arbitration under the SCC Rules
  • a consumer goods company in a post M&A dispute under the ICC Rules
  • an energy company in a dispute under the LCIA-MIAC Rules in relation to a power purchase agreement
  • a telecoms company in a post M&A dispute under the LCIA Rules
  • a Russian bank in relation to a potential arbitration under the SCC Rules
  • a pharmaceutical company in connection with the termination of a distribution agreement for the Middle East region