David Davis has suggested he has changed his mind over military intervention in Syria in the wake of a suspected chemical attack, after he voted against similar action when David Cameron was prime minister.

The Brexit secretary said he had been given reassurance that any doubts on possible airstrikes would be addressed when Theresa May summons her most senior MPs for an emergency cabinet meeting on Thursday afternoon.

Ministers will be asked to consider Britain’s response to the escalating crisis in Syria, following the alleged use of chemical weapons by the Syrian regime in the city of Douma, in Eastern Ghouta, last week, where more than 40 people were killed and scores injured.

Speaking in London, Mr Davis said no decision had been taken on whether there would be a joint response by the UK and US and other allies against the Syrian regime, but he was reassured that he would be given the necessary evidence at the meeting of the prime minister’s top team later today.

Outlining why he had previously voted against action, he said: “One was because he [Mr Cameron] hadn’t provided the evidence and intelligence that we knew who it was, and secondly because there was not a proper plan, which was thought through properly.

“Those two things, I am assured, we’re going to answer today.”

Mr Davis was among MPs who rejected possible UK military action in Syria in 2013, after a suspected chemical weapons attack outside Damascus where hundreds of people died.

He told a Wall Street Journal conference: “The situation in Syria is horrific, the use of chemical weapons is something the world has to prevent.

“But also it’s a very, very delicate circumstance and we’ve got to make this judgment on a very careful, very deliberate, very well thought-through basis.”

Opposition leaders have called for a parliamentary vote before any new military action in Syria amid speculation Ms May could authorise UK forces to back US-led action before MPs return from their Easter recess next week.

Labour leader Jeremy Corbyn said MPs must be consulted, adding: “Surely the lessons of Iraq, the lessons that came there from the Chilcot Report, are that there’s got to be, there has to be, a proper process of consultation.

“We elect Parliament, we elect members of Parliament. They should have a voice in this. Cabinet on its own should not be making this decision.

“The dangers of bombing now, which could escalate the conflict beyond belief. Just imagine the scenario if an American missile shoots down a Russian plane or vice versa. Where do we go from there?”

Liberal Democrat leader Sir Vince Cable also urged caution over British involvement, as he pointed to the dangers of Russian involvement and Mr Trump’s “erratic” behaviour.

And SNP leader at Westminster Ian Blackford told the BBC: “There is no mandate for the Government to take this action.

“And, I would simply say to the Prime Minister: be very careful, because you do not have a majority in Parliament.

“You are a minority Government, and you need to seek the consent of Parliament before you commit the United Kingdom to any action.”

The US is preparing options for an attack on Syria, as relations with Russia, one of the regime’s only international allies, plunged to new lows.

President Donald Trump told Russia to “get ready” for US missiles and warned Moscow it “shouldn’t be partners with a Gas Killing Animal”, referring to Syrian president Bashar al-Assad.

French president Emmanuel Macron said he has proof that the Syrian government used chemical weapons on the rebel-held town, an allegations that has been strongly denied by the Assad regime.

Ms May toughened her rhetoric over the attack on Wednesday, appearing to directly blame the Syrian regime for the Douma attack.

She said: “All the indications are that the Syrian regime was responsible and we will be working with our closest allies on how we can ensure that those who are responsible are held to account and how we can prevent and deter the humanitarian catastrophe that comes from the use of chemical weapons in the future.

“The continued use of chemical weapons cannot go unchallenged.”

It comes almost a year after dozens of people were killed in an chemical attack in the northern town of Khan Sheikhoun, prompting Mr Trump to order the firing of several missiles as a Syrian air base.