Theresa May recalls ministers as Britain weighs Syria action

May will reportedly seek her ministers' approval to join allies in targeting President Bashar Assad's regime as US President Donald Trump warned that missiles "will be coming" and France also weighs strikes.

May had avoided apportioning blame for the alleged attack in the rebel-held city of Douma on Saturday, but on Wednesday said: "All the indications are that the Syrian regime was responsible."

She continued: "The use of chemical weapons cannot go unchallenged. We will be working with our closest allies on how we can ensure that those who are responsible are taken to account."

May summoned ministers for an emergency cabinet meeting on Thursday afternoon "to discuss the response to events in Syria", her office confirmed.

However, some of her MPs have expressed caution about getting involved in the complex conflict in Syria and are pressing for parliament to be recalled from its Easter break to discuss any action.

Several British newspapers reported that Royal Navy submarines armed with cruise missiles were moving into range to be ready to take part in any strike.

The Times and the Daily Telegraph newspapers reported that the cabinet was expected to back May in joining any US-led action.

However, it is believed there are no plans to recall MPs, who are not due to return to parliament until Monday, to give their approval.

"The situation in Syria is horrific, the use of chemical weapons is something the world has to prevent," Brexit minister David Davis said on Thursday morning.

"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."

British MPs warn of escalation

Britain is currently part of a US-led coalition conducting airstrikes against the Islamic State group in Iraq and Syria, and has conducted more than 1,700 such attacks.

The mission was only allowed after approval by MPs - they backed military action in Iraq in September 2014, and in Syria a year later, strictly limiting strikes to IS targets.

Action against the Syrian regime itself was ruled out in a parliamentary vote in 2013, and many MPs have called for a vote before any action this time.

"Parliament should always be given a say on any military action," opposition Labour leader Jeremy Corbyn told the BBC.

"What we don't want is bombardment which leads to escalation and leads to a hot war between Russia and America over the skies of Syria."

Formally, the British prime minister has the right to go to war without approval from parliament, but a convention has been established in previous conflicts where MPs have a vote either before or shortly after military action begins.

Many MPs have called for Britain to act against Syria, warning that the use of chemical weapons was in breach of international law and could not be allowed to go unpunished.

The crisis has evoked memories of the Iraq War, which was approved by parliament and left 179 British soldiers dead and unleashed years of sectarian violence.

A YouGov poll in The Times conducted this week found that 43 percent of voters oppose strikes in Syria, with 34 percent unsure and only 22 percent supportive.

Some members of May's Conservative party have urged caution of intervening in a highly complex situation with many different players.

"What we've got here in Syria is a choice between monsters on the one hand and maniacs on the other," Julian Lewis, the chairman of the House of Commons defence committee, told the BBC.

Another Conservative MP, former London mayoral candidate Zac Goldsmith, tweeted: "We need a clear response to the Syrian chemical outrage.

"But parliament must be involved before any military action is agreed. Specifically the govt needs to explain who is strengthened if and when Assad is weakened. And what happens after."