Updated: 12/04/18 : 14:02:09
Theresa May has summoned ministers to an emergency cabinet meeting to discuss the UK's response to the suspected chemical weapons attack in Syria.
Ministers are expected to back her call to join military action threatened by the United States and its allies.
Sources say the PM is prepared to take action against the Assad regime without first seeking Parliamentary consent.
But there have been calls from opposition parties and some Tories for MPs to get a vote beforehand.
Labour leader Jeremy Corbyn said: "More bombing, more killing, more war will not save life. It will just take more lives and spawn the war elsewhere."
Mrs May has said "all the indications" are that the Syrian regime of president Bashar al-Assad, which denies mounting a chemical attack, was responsible for the alleged chemical attack in the formerly rebel-held town of Douma.
Senior figures from Russia, which provides military support to the Syrian regime, have warned of a Russian response to a US attack.
BBC political correspondent Iain Watson said Mrs May appeared to have made up her mind and that it was "a question of when, not if" there will be military action.
If the cabinet approves UK involvement, that would open the way for British forces to join an operation against Syrian targets that US President Donald Trump has said in a tweet "will be coming".
Mr Corbyn criticised the US president's rhetoric, saying: "I think the whole world should be alarmed at that sort of instant reaction - sending stuff out on social media to make policy."
In a subsequent tweet on Thursday, the US president said an attack on Syria "could be very soon or not so soon at all".