The cabinet has unanimously backed Theresa May’s warning that Syria’s use of chemical weapons could not go unchallenged, leaving the way open for British participation in military action against Bashar al-Assad’s regime.



Downing Street said senior ministers had agreed it was highly likely the Syrian government was responsible for the “shocking and barbaric” gas attack on the rebel-held town of Douma, which killed up to 75 people.

Within hours of the meeting, the prime minister spoke to Donald Trump by phone about the crisis, with the two leaders agreeing to work closely together on the international response. They stressed that Syria must be prevented from launching a similar onslaught on its own people in future.

The Labour leader, Jeremy Corbyn, accused the government of waiting for instructions from the US. He said: “Further UK military intervention in Syria’s appalling multi-sided war risks escalating an already devastating conflict. The government appears to be waiting for instructions from President Donald Trump on how to proceed. But the US administration is giving alarmingly contradictory signals.”

At a two-hour cabinet meeting on Thursday, ministers backed plans to take further action – along with the US and France – to prevent Assad’s forces from launching such an “appalling and inhumane” attack again.

Cabinet ministers emerged tight-lipped from the unusually long meeting as No 10 awaited the next move from the White House, where Trump had convened a meeting of his own national security council.

After the call to the White House, No 10 said: “The prime minister spoke to President Trump about Syria this evening. They agreed that the Assad regime had established a pattern of dangerous behaviour in relation to the use of chemical weapons.

“They agreed it was vital that the use of chemical weapons did not go unchallenged, and on the need to deter the further use of chemical weapons by the Assad regime. They agreed to keep working closely together on the international response.”

Trump was also expected to speak to the French president, Emmanuel Macron, about what form the action could take, with the White House saying: “No final decision has been made.” It is understood the prime minister wants the UK to play a central role in any action, rather than just supporting France and the US.

Although preparations are shrouded in secrecy, training exercises were clearly already under way at RAF Akrotiri in Cyprus in preparation for a possible counterattack by the Russians, close allies of the Syrian regime.



However, the transport minister, Jo Johnson, brother of the foreign secretary, told BBC’s Question Time: “There has been no decision to take military action at this point.”

The prime minister is thought to be unlikely to consult parliament before any coordinated military action, which is likely to provoke anger from the opposition benches and to divide the public. However, the cabinet’s backing could give her some political cover to take further action.

After the meeting at No 10, a Downing Street spokesman said: “Cabinet agreed that the Assad regime has a track record of the use of chemical weapons and it is highly likely that the regime is responsible for Saturday’s attack. Cabinet agreed it was vital that the use of chemical weapons did not go unchallenged.



“[They] agreed on the need to take action to alleviate humanitarian distress and to deter the further use of chemical weapons by the Assad regime. Cabinet agreed the prime minister should continue to work with allies in the United States and France to coordinate an international response.”



The US defence secretary, James Mattis, said Washington was still looking for evidence on who carried out Saturday’s chemical weapons attack in Damascus and said his main concern about a military response was how to stop it escalating out of control. However, Macron said on Thursday that his government had evidence that Assad’s government was responsible.

Earlier, the Brexit secretary, David Davis, said he expected the cabinet to be provided with evidence showing that the Syrian regime was behind the attack and also that the prime minister would set out a properly thought-through plan.

Davis, who voted against military action against the Assad regime in 2013, said: “The situation in Syria is horrific – the use of chemical weapons is something the world has to prevent. We of all countries in the world, after the Skripal affair, have perhaps the most immediate knowledge of it apart from the Syrians themselves. We’ve got very delicate circumstances and we’ve got to make a judgment on a very careful, very well-thought-out, well-thought-through basis.”

Referring to the 2013 vote, he said that there were two reasons for his opposition: “We had not provided the evidence and the intelligence that we knew who it was, and secondly there was not a proper plan thought through properly. Those two things I’m assured we’re going to answer today.”

The foreign secretary, Boris Johnson, withdrew from a press conference in Oxford with his German counterpart, Heiko Maas, to attend the emergency cabinet, instead meeting him briefly at Heathrow.

On Thursday, May was also given the backing of her most influential foreign policy backbencher, Tom Tugendhat, to take part in any western strike against Syria without a Commons mandate. However, Conservative backbenchers including Zac Goldsmith have expressed reservations about taking action without a vote.

The SNP’s Westminster leader, Ian Blackford, said a parliamentary debate should take place before, rather than after, military action was launched.