A British court said Thursday that the U.K. can transfer sovereignty over the contested and strategically located Chagos Islands to Mauritius, overturning a block that was imposed hours before the agreement was due to be signed.

High Court judge Martin Chamberlain said after a hearing on Thursday that an injunction barring the handover should be removed. He said “the public interest and the interests of the United Kingdom would be substantially prejudiced” if there was a further delay.

The U.K. government welcomed the ruling, saying “this deal is vital to protect the British people and our national security.”

The U.K. has agreed to hand Mauritius the Indian Ocean archipelago, which is home to a strategically important naval and bomber base on the largest of the islands, Diego Garcia. The U.K. would then lease back the base for at least 99 years.

The agreement was due to be signed by British Prime Minister Keir Starmer and Mauritian leader Navin Ramgoolam at a virtual ceremony on Thursday morning.

But a judge granted an injunction in the early hours of Thursday, blocking the British government from taking any “conclusive or legally binding step” to hand the islands to a foreign government.

The injunction came in response to a claim by two Chagossian women representing the islands’ original residents, who were evicted decades ago to make way for the American base. Bernadette Dugasse and Bertrice Pompe, both British citizens, fear it will become even harder to return once Mauritius takes control of the islands.

After the injunction was lifted, Pompe said it was “a very sad day,“ but vowed to continue fighting.

“We do not want to hand over our rights to Mauritius. We are not Mauritians,” she said outside the High Court.

“The rights we are asking for now, we have been fighting for for 60 years,” she added. “Mauritius is not going to give that to us.”

One of the last remnants of the British Empire, the Chagos Islands have been under British control since 1814. Britain split the islands away from Mauritius, a former British colony, in 1965, three years before Mauritius gained independence.

Britain evicted as many as 2,000 people from the islands in the 1960s and 1970s so the U.S. military could build the Diego Garcia base, which has supported U.S. military operations from Vietnam to Iraq and Afghanistan.

Displaced Chagossians fought unsuccessfully in U.K. courts for years for the right to go home. Under the deal, a resettlement fund would be created to help displaced islanders move back to the islands, apart from Diego Garcia. Details of any such measures remain unclear.

Mauritius has long contested Britain’s claim to the archipelago and in recent years the United Nations and its top court have urged Britain to return the Chagos to Mauritius, around 2,100 kilometers (1,250 miles) southwest of the islands.

In a non-binding 2019 opinion, the International Court of Justice ruled that the U.K. had unlawfully carved up Mauritius when it agreed to end colonial rule in the late 1960s.

The British government says those rulings put the future of the Diego Garcia base, vital to U.K. security, at stake. Negotiations on handing the islands to Mauritius began in 2022 under the previous Conservative government and resumed after Starmer’s Labour Party was elected in July.

A draft agreement was struck in October, but was delayed by a change of government in Mauritius and reported quarrels over how much the U.K. should pay to lease the base.

The U.K. also paused to consult the U.S. after the change of government in Washington. President Donald Trump’s administration gave its approval.

The U.K.’s opposition Conservatives have criticized the deal, accusing the government of surrendering sovereignty over a British territory.

“We should not be paying to surrender British territory to Mauritius,” Conservative leader Kemi Badenoch said.