Keir Starmer has insisted the Falkland Islands “will remain British” just days after failing to give that guarantee.
The Labour leader clarified his position at prime minister’s questions on Wednesday.
A furious row broke out last Thursday after the government announced that it was handing over sovereignty of another overseas territory, the Chagos Islands, to Mauritius.
At a press conference the following day, the prime minister was asked whether that meant the Falkland Islands and Gibraltar could be next, but dodged the question.
But at PMQs, he said he had personal reasons for wanting to see the Falkland Islands remain under British control, despite Argentina’s claim to the territory.
He said: “My uncle nearly lost his life when his ship was torpedoed defending the Falklands. They are British and they will remain British.
“And sovereignty in Gibraltar is equally not to be negotiated...I’ve been very clear about the Falklands. It’s personal to me.”
Britain fought a war in 1982 after the Falkland Islands were invaded by Argentina.
A referendum held in 2013 found that more than 90% of those living there wanted to remain British.