Opposition Day: British Indian Ocean Territory

Parliament voted on 26 February 2025 to reject an Opposition Day motion on the British Indian Ocean Territory (BIOT), by 298 votes to 147. Opposition Day motions are a parliamentary device that lets the opposition choose the subject of debate and force a vote, in this case directed at the Labour government's handling of the Chagos Islands sovereignty question and its proposed agreement to transfer the islands to Mauritius. The vote matters because the Chagos Islands host Diego Garcia, one of the most strategically significant military bases in the world, used jointly by the UK and the United States. Critics of the government's deal argue that transferring sovereignty to Mauritius risks the long-term security of that base and weakens Britain's strategic position in the Indo-Pacific. Supporters of the government's approach argue the deal, if concluded, secures Diego Garcia's future on a firm legal footing and avoids a prolonged and potentially losing legal battle over sovereignty. The vote divided along sharply partisan lines. Every Conservative MP who voted backed the motion, as did all voting Liberal Democrats, Reform UK members, and one Democratic Unionist Party member. Every Labour and Labour and Co-operative MP who voted opposed it, joined by the four Green MPs and two independents. With 97 Labour MPs and 18 Liberal Democrats recording no vote, the government's majority was not threatened. The result reflects the opposition's use of parliamentary time to put pressure on the government over a deal that has attracted sustained criticism from across the right of British politics.