Labour's "activist" Attorney General Lord Hermer could block the US from bombing Iran through the Chagos Islands "surrender" deal.
Hermer, who controversially declared "international law is the rule of law writ large" and has compared its critics to Nazis, is the Government's most senior legal adviser - and could play a pivotal role in how deeply Britain is involved in the growing conflict between Israel and Iran.
But it's not just the UK.
Lord Hermer is poised to deliver his verdict on whether the US can send its jets over from the Chagos Islands to destroy Iran's remaining underground nuclear sites.
Under the terms of the "surrender" deal, in which Hermer was deeply involved, the President must obtain the permission of the Prime Minister to launch an attack from the joint UK-US military base at Diego Garcia. The terms of the deal also include a commitment to Article 4 of international law.
GB NEWS
The Prime Minister, in turn, seeks the advice of his Attorney General on whether such permission would be legal.
Just this morning, Labour minister Miatta Fahnbulleh reaffirmed that Sir Keir Starmer's commitment to international law.
The PM "will do everything in accord with international law", she said.
"Legal advice is for the Prime Minister, and I think that's where it will stay," she told Times Radio. "What I will say is that we have a Prime Minister who is a lawyer - and a human rights lawyer."
The AG is said to have informed the PM that Britain's involvement should be limited to defending Israel, not striking Iran.
LATEST ON LABOUR'S LORD HERMER:
The AG is said to have informed the PM that Britain's involvement should be limited to defending Israel
PA
Thus, with the pair apparently aligned on adhering to international law, American jets could be forced to stay on the ground if Hermer deems the former has been violated.
This would be a strategic blow for the US as the Air Force B-2 bombers that carry the bunker-buster bombs needed to destroy Iran's subterranean nuclear facilities are refuelled at a limited number of bases, one of them being Diego Garcia.
Asked on Thursday whether the Government would block American planes taking off from the UK-US base on the islands, a Downing Street spokesman said: "I'm not going to get into hypothetical situations and I'm not going to speculate."
The US military could also request the use of the RAF base in Akrotiri, Cyprus, for refuelling its planes.
Any UK refusal by the British could cast significant doubt on American military action and even place the "special relationship" under pressure.
MORE MEMBERSHIP STORIES AS IRAN-ISRAEL HEATS UP:
PICTURED: Keir Starmer visits the British RAF base in Akrotiri, Cyprus. The US military could also request the use of RAF Akrotiri for refuelling
PAAnd in a further blow to potential American strikes on Iran, the UK could be forced to inform Iranian-aligned Mauritius of military action from the Chagos Islands before it happens.
The treaty says that Britain "agrees to expeditiously inform Mauritius of any armed attack on a third state directly emanating from the base on Diego Garcia".
Philippe Sands, an international lawyer who previously acted for Mauritius against Britain, confirmed to the House of Lords just days ago that the deal could be interpreted as meaning that Britain must give the island nation due notice before an attack takes place.
The Attorney General's office said: "By long-standing convention, reflected in the ministerial code, whether the law officers have been asked to provide legal advice and the content of any advice is not routinely disclosed.
"The convention provides the fullest guarantee that government business will be conducted at all times in light of thorough and candid legal advice."
Most Read
