LONDON — The British government’s plans to hand control of the strategically significant Chagos Islands to Mauritius are set to be signed off on Thursday, after an 11th-hour legal injunction failed to stop an effort that has been intensely controversial in both the United Kingdom and the United States.

Prime Minister Keir Starmer intends to return the islands to the African country, while maintaining control of the US-UK Diego Garcia military base, and the deal is expected be finalized on Thursday.

It comes after a High Court judge briefly blocked the move in a ruling made at 2 a.m. local time (9 p.m. ET on Wednesday). The deal was challenged by Bernadette Dugasse and Bertrice Pompe, Chagossian women living in Britain who opposed the deal on human rights grounds.

The UK’s negotiations with Mauritius over the Chagos Islands have been convoluted and controversial.

Starmer’s government announced its plans to sell the islands to the East African country soon after taking office last year, framing it as a long-awaited solution to a colonial-era arrangement that had posed an ethical and legal dilemma.

London is expected to pay billions of pounds to close the deal, and Mauritius is heavily reliant on imports from China, which has raised national security concerns on both sides of the Atlantic.

Grant Shapps, a former Conservative defense minister, told CNN earlier this year that the plan was “insane.”

“(China) will use territory to expand their influence. They will spy,” Shapps told CNN. “A lot of sensitive stuff goes on at British military bases. So you don’t want to be surrounded by potential adversaries.”

Critics of the deal were given unlikely hope just hours before it was set to be completed, with the temporary injunction leaving plans in the balance.

At a full hearing later on Thursday morning, a Foreign Office lawyer told the court: “My instructions from Number 10 are that we need a decision by 1 p.m. today if we are to sign today, and everybody is standing by,” according to the PA Media news agency, which was present in the courtroom.

The lawyer argued the deal provided “obvious” benefits to the UK and US national security interests. “Diego Garcia is an essential and utterly important base from which the United States and the United Kingdom, very often jointly, operate, and therefore the preservation of that facility is of the utmost importance to UK national security,” he said.

Dugasse and Pompe have meanwhile criticized the government for negotiating on the future of the islands without consulting the exiled Chagossian community.

Last year Pompe, who lives in London, told the BBC: “I’d love to go back... I’d love to go there for longer than one week ... the UK is not my country but I have to be here just to try get back to where I belong.”

Britain has controlled the region since 1814, and in 1965 it split the Chagos Islands from Mauritius before that former colony became independent. London kept control of the archipelago and renamed it as the British Indian Ocean Territory.

It then evicted almost 2,000 residents to Mauritius and the Seychelles to create space for an airbase on the largest island, Diego Garcia, which it leased to the United States. The secretive base is important to Washington’s interests, giving it a significant military presence in the Indian Ocean.

But its future was thrown into uncertainty in 2019, when the International Court of Justice (ICJ) ruled Britain should return the islands “as rapidly as possible,” so that they could be decolonized in “a manner consistent with the right of peoples to self-determination.” That ruling was advisory, but it was endorsed overwhelmingly by the United Nations General Assembly. — CNN