British PM to tell MPs Saturday's strikes were in national interest and to prevent further suffering, but will refuse calls for a vote on military action
Theresa May will insist on Monday that bombing Syria was in Britain's national interest and has strong international support, as Labour MPs continue to question the legality of the bombing raid.
The British prime minister is expected to face angry MPs in parliament after launching military action early on Saturday without securing the support of the House of Commons.
She will say the UK joined the US and France in strikes following the 7 April chemical weapons attack in Douma to "alleviate further humanitarian suffering".
In an unusual move, May will ask for an emergency debate to allow more time for discussion - an acknowledgment of the anger among MPs at not being consulted.
However, the debate is expected to fall short of an explicit vote on the military action.
"There is broad based international support for the action we have taken," she will say, according to British media.
Germany, Italy, Canada, Australia and European Council President Donald Tusk have "all have expressed their support for the actions that Britain, France and America have taken", the prime minister will add.
UN Security Council-mandated inspectors have probed previous chemical attacks and decided Bashar al-Assad's military was responsible four times, MPs will be told.
"We are confident in our own assessment that the Syrian regime was highly likely responsible for this attack and that its persistent pattern of behaviour meant that it was highly likely to continue using chemical weapons," May will add.
"Furthermore, there were clearly attempts to block any proper investigation, as we saw with the Russian veto at the UN earlier in the week.
"And we cannot wait to alleviate further humanitarian suffering caused by chemical weapons attacks.
"It is in our national interest to prevent the further use of chemical weapons in Syria - and to uphold and defend the global consensus that these weapons should not be used.
"For we cannot allow the use of chemical weapons to become normalised - either within Syria, on the streets of the UK or elsewhere."
Theresa May is to call for an emergency debate in parliament over Syria (Reuters)
Speaking before the debate, Boris Johnson, the British foreign secretary, told reporters that the strikes were "right for the UK and right for the world".
Johnson, speaking at a summit of European Union foreign ministers, stressed it was "not an attempt to change the tide of the war in Syria or to have regime change" and "the Syrian war in many ways will go on in its horrible, miserable way".
"But it was the world saying that we have had enough of the use of chemical weapons, the erosion of that taboo that has been in place for 100 years has gone too far under Bashar Assad," he said.
But shadow attorney general Baroness Chakrabarti questioned the government's justification for the air strikes on Monday, telling BBC Radio 4's Today programme: "You can't use force under international law just to punish Syria for bad behaviour.
"I think that Parliament should have been recalled before the strike. Some people will suspect that that didn't happen because of governmental concerns that they couldn't get the vote in Parliament. And that to me is not a good enough reason."
Opposition calls for Commons approval
Labour leader Jeremy Corbyn has called for the introduction of a War Powers Act to stop governments launching military action in most circumstances without the backing of the Commons.
The Labour leader said chlorine has been used by "a number of parties in the conflict" in Syria as a weapon and questioned the legality of the air strikes.
However, the international development secretary, Penny Mordaunt, has opposed those calls.
Mordaunt told the BBC: "To take a decision on whether something is legally justified, and whether what we are actually intending on doing in terms of targets is appropriate, you would need to know information that could not be shared with every MP.
"And so, outsourcing that decision to people who do not have the full picture is, I think, quite wrong. And, the convention that was established, I think is very wrong.
Outsourcing that decision to people who do not have the full picture is, I think, quite wrong
- Penny Mordaunt, international development secretary
"You can't, for example, share targets with members of parliament. It would be a crazy thing to do.
"I support governments being able to take those decisions. Parliament should hold government to account for that decision."
The prime minister spoke in Downing Street in the hours after the Saturday attacks and insisted the action was limited and targeted to degrade chemical weapons capabilities and deter the Syrian government from further attacks.
But she also drew a link with the nerve agent attack on Russian former spy Sergei Skripal and his daughter Yulia in Salisbury, which Britain and its international partners say was ordered by the Kremlin.
Russian TV claims Skripal poisoning & Syria strike are "part of the same Anglo-Saxon provocation". That phrase on the screen behind is being used more & more in the state media here: "The Englishwoman spoils everything!" pic.twitter.com/2K8uJjbRNM
— Steve Rosenberg (@BBCSteveR) April 15, 2018
Russian state television at the weekend said both the Skripal and Syrian chemical attacks were "part of the same Anglo-Saxon provocation".
Russia's president, Vladimir Putin, said on Sunday that further Western attacks on Syria would bring chaos to world affairs.
In a telephone conversation with his Iranian counterpart, Hassan Rouhani, Putin and Rouhani agreed that the Western strikes had damaged the chances of achieving a political resolution in the seven-year Syria conflict, according to a Kremlin statement.
"Vladimir Putin, in particular, stressed that if such actions committed in violation of the UN Charter continue, then it will inevitably lead to chaos in international relations," the Kremlin said.
Meanwhile, Whitehall sources have confirmed a 20-fold increase in "disinformation" spread by Kremlin-linked social media "bot" accounts since the strikes, according to The Daily Telegraph.
The British foreign secretary said the UK has to "take every possible precaution" to prepare for possible revenge cyber attacks on targets like the NHS and electrical facilities.