However, Sir Keir was criticised by Conservative leader Kemi Badenoch for “dither and delay”, and she urged him to stand fully behind the US.
She said: “On Saturday, our allies in Australia and Canada immediately backed the action of taken by America against this despotic regime in Tehran, and I have made it very clear that the Conservative party also stands behind America taking this necessary action against state-sponsored terror.”
Reform UK’s deputy leader Richard Tice said Iran had been “a permanent threat” to Britain and Trump’s strikes had “done the West a huge, huge favour”.
Accusing the prime minister of looking weak, he said: “Does he understand that actually, in refusing to support the US, he has humiliated us on the international stage.”
On the other hand, the prime minister’s decisions were criticised by parties on the left, including Liberal Democrat leader Sir Ed Davey, who said failing to stand up to Trump “makes our country less safe”.
He said: “We have seen before what happens when an American president launches an illegal war with no idea how or when it is going to end, and we fear for what comes next.”
Green foreign affairs spokeswoman Ellie Chowns condemned the “deeply irresponsible and illegal attack by the US and Israel on Iran”.
“The UK must stand unequivocally against this reckless action,” she said, calling for a parliamentary vote on “any UK involvement in this war”.
“We are not at war,” the prime minister responded, adding: “We are not getting involved in offensive action that the US and Israel are taking.”
Scotland’s First Minister John Swinney put out a statement criticising Sir Keir’s decision to allow the US to use military bases, which he said “creates further risks and dangers”.
Officials have urged Britons, including holidaymakers and business people, to register their presence in the Middle East with the UK government, with more than 100,000 having done so.
No evacuation of British citizens is imminent but the Foreign Office is making plans in case commercial flights remain grounded across the Gulf countries.
