The Prime Minister said Labour leader Jeremy Corbyn’s call for a War Powers Act would “seriously compromise” national security.
Mr Corbyn faced a hostile reception from Tory MPs in an emergency debate on Parliament’s role in authorising military action, following air strikes on the Syrian government ordered without Westminster’s approval.
The Labour leader failed in his bid to send a message to the government by asking MPs to oppose his own motion, with the government winning a symbolic vote by 317 to 256. Fifty Labour MPs refused to back their leader.
The Prime Minister defended her decision to take action without seeking Parliament’s approval, saying that coming to the Commons beforehand would have compromised the “effectiveness of our operations and safety of British servicemen and women”.
She said a War Powers Act would mean smaller scale and targeted military action such as that over the weekend in Syria “would become unviable”.
“Making it unlawful for Her Majesty’s Government to undertake any such military intervention without a vote would seriously compromise our national security, our national interests and the lives of British citizens at home and abroad,” Mrs May said.
“And for as long as I’m Prime Minister, that will never be allowed to happen.”
Mr Corbyn said a War Powers Act could “specify at what point in decision-making processes MPs should be involved, as well as retaining the right of ministers to act in an emergency or in the country’s self defence”.
Tory MP Andrew Bridgen drew laughs in the Commons with a sideswipe at Mr Corbyn, suggesting the Labour leader would not authorise military action even if the Isle of Wight were invaded.
And Mrs May attracted cheers from the Tory benches with her response to a question from Labour MP Karen Lee, who suggested US president Donald Trump had more say over UK foreign policy than MPs.
Concluding her speech, the Prime Minister said a “clear majority” of the Commons believe the government “did the right thing”.
“I realise that for some in this House, and especially for those who have not had to do what I have to, the attractive purity of a democratic principle that Parliament should always decide may still appeal more than the practice of how to ensure an effective military operation that delivers our national interest,” she said.
But Mrs May said she hoped MPs could agree on her “commitment as Prime Minister to being held to account by this House for the decisions that I’ve taken”.
SNP Westminster leader Ian Blackford criticised the “failure” of the government to recall Parliament, adding it was to be “deeply regretted” that the “only people that haven’t had a voice” were MPs.
He said: “Nobody is talking about compromising operational activity, it’s about the principle of Parliament giving its consent to military action.”
Meanwhile, Saudi Arabia’s foreign minister said the kingdom was in talks with the Trump administration about sending forces into Syria, and this proposal has been under discussion since the Obama administration.
Adel al-Jubeir told reporters yesterday: “We are in discussions with the US and have been since the beginning of this crisis about sending forces into Syria.”