Sir Keir Starmer faces calls to rule out allowing the US to use British bases to support an attack on Greenland, as Washington continues to threaten to take over the territory.
US officials have said they could use “military means” to “acquire” the semi-autonomous Danish territory, which President Donald Trump claims is vital for national security.
Liberal Democrat leader Sir Ed Davey called on the Prime Minister to rule out British support for such action, saying the UK “must never play midwife to American aggression directed against our Nato allies”.
He said he was “deeply concerned” that Sir Keir was yet to rule out the use of British bases, and said the Prime Minister should “spell out to Trump and his lawless cabinet that the UK will never support such a dangerous act”.
Sir Ed’s comments come a day after UK bases and military personnel supported a US operation to seize an oil tanker in the Atlantic, said to be part of a “shadow fleet” seeking to evade sanctions on Iranian oil.
Downing Street declined to comment on Sir Ed’s demand, saying it was “slightly hypothetical”, but added the Prime Minister had set out his position on Greenland “very clearly”.
Sir Keir has said Greenland’s future must be a matter for the people of the territory and Denmark alone, including in a phone call with Mr Trump on Wednesday described by Downing Street sources as “positive” and “friendly”.
Meanwhile, Cabinet ministers have said the US remains a reliable ally despite fears that a move against Greenland would spell the end of the Nato alliance.
Education Secretary Bridget Phillipson told broadcasters on Thursday that the US was “a close and very trusted partner of our nation”.
Her Cabinet colleague Pat McFadden said: “The United States is a reliable ally. We believe that to be the case, we see that every day.”
Deputy Prime Minister David Lammy is expected to underline the closeness of the “special relationship” later on Thursday at a meeting with US vice-president JD Vance in Washington.
The meeting, at which Greenland is likely to feature, forms part of Mr Lammy’s visit to the US to mark the 250th anniversary of America’s declaration of independence from Britain.
The two men are long-standing friends, and Mr Lammy hosted Mr Vance and his family last year at Chevening, his grace-and-favour house in Kent.
