The top judge on the European Court of Human Rights said Thursday that the United Kingdom had a legal obligation to implement any rulings the court issues blocking deportations of migrants to Rwanda.
In June 2022, the ECHR issued an so-called interim measure blocking the UK from removing asylum seekers to Rwanda, threatening a key pillar of the British Conservative government's plan to limit migration.
The measure, issued under rule 39 of the Strasbourg-based court, is an urgent ruling handed down only when the ECHR deems there is imminent risk of irreparable harm to a plaintiff.
With an election expected in the UK this year, Prime Minister Rishi Sunak has vowed to carry out the first deportation flight to Rwanda in the coming months.
ECHR President Siofra O'Leary, speaking at the court's annual press conference, indicated that the UK, as a signatory of the European Convention on Human Rights, would be breaking international law if it flouted such rulings from the court.
"There is a clear legal obligation under the Convention for states to comply with rule 39 measures," she said.
"The court issues interim measures... in exceptional circumstances where there is a real and imminent risk of irreparable harm."
She said that states which in the past "failed to comply" with such interim measures were later found by instances of the court to "have violated their obligations" under the Convention.
In London, Sunak's spokesperson said that after recent changes the government was "confident our legislation is compliant with our international obligations" and "there should be no need" for the ECHR to block flights again.
But the spokesperson made clear that ministers would be prepared not to comply as "we do not think foreign courts should stop flights taking off".
The Conservative government introduced a bill to parliament after the UK Supreme Court ruled late last year that deporting asylum seekers to Rwanda is illegal under international law.
O'Leary said the UK had in the past complied with interim measures throughout the court's history and had "publically declared the need for other states to comply" with such rulings.
She said the most recent example of this was in 2021, when the UK urged Russia to comply with a ruling ordering the release of opposition figure Alexei Navalny, which was ignored by Moscow.
The ECHR is part of the 46-member Council of Europe, which regards it as a court of last instance whose rulings members are obliged to implement. Russia left the Council in the wake of its invasion of Ukraine.
