British Prime Minister Theresa May summoned her Cabinet back from vacation Thursday to discuss military action against Syria over an alleged chemical weapons attack.

May has indicated she wants Britain to join in any U.S.-led strikes in response to the attack in Douma. She has said all the indications” are that President Bashar Assad’s forces were responsible, and the use of chemical weapons “cannot go unchallenged.”

The U.S., France and Britain have been consulting about launching a military strike, and President Donald Trump tweeted Wednesday that missiles “will be coming.” On Thursday, Trump tweeted that an attack “could be very soon or not so soon at all!”

Britain’s Ministry of Defense refused to comment on reports that Royal Navy submarines armed with cruise missiles have been dispatched into range of Syria.

British opposition lawmakers called for Parliament to be given a vote before any military action. May isn’t legally required to do that, though it has become conventional since the 2003 invasion of Iraq for lawmakers to be given the chance to vote before British forces are deployed.

Parliament is in recess until Monday, though it could be called back early for an emergency debate.

Ian Blackford, who heads the Scottish National Party group in Parliament, said May “presides over a minority government that has no majority or mandate for military action, and there must be no attempt to bypass Parliament.”

There is no guarantee lawmakers would rubber-stamp a decision for military strikes. In 2013, Parliament defeated a call by then-Prime Minister David Cameron for airstrikes in response to an earlier chemical attack in Syria. In 2015 lawmakers approved U.K. strikes on Islamic State group targets in Syria, but not on government forces.

Brexit Secretary David Davis, who voted against military action in 2013, said Thursday that “no decision has been taken.”

He said “we’ve got to make this judgment on a very careful, very deliberate, very well thought-through basis, knowing exactly … how strong the evidence is.”

(AP)