Theresa May has faced a shock claim she "manipulated" pro-bombing Labour MPs by showing them secret intelligence on Syria.
The Prime Minister was accused of showing favouritism to MPs who agree with her decision to launch airstrikes on the war-torn country.
The claim was raised as Mrs May clashed today with Jeremy Corbyn - who branded the strikes legally questionable - in furious scenes in the House of Commons.
Labour's leader accused her of a "flagrant disregard" for MPs and "tossing aside" convention by not giving them a vote before the strikes on Saturday.
And Mrs May was forced to furiously deny "taking instructions" over the raid from US President Donald Trump.
The US, UK and French strikes hit three chemical weapons sites in Syria in retaliation for a poison attack that killed dozens including children in the town of Douma.
Opposition leaders were offered a secret briefing on "Privy Council" terms before the bombing raids took place.
But SNP MP Stewart McDonald accused the government of "selectively offering intelligence and security briefings".
He told the Commons: "These briefings appear to have been offered to members of the Labour opposition not on the basis of privy counsellor status.
"But on the basis of those Opposition members who are sympathetic to the Government's position.
"That leads to concerns that the Government is using intelligence briefings to manipulate Parliament.
"And to bolster its own case for its behaviour on the Opposition benches - not on security terms, but on politics."
Prime Minister Theresa May appeared to deny the claim.
She said: "My understanding is that any intelligence briefings that have been given have been given to Privy Council members of this House and all Privy Council members of this House have been invited to attend such briefings."
Pressed further on the issue by Mr McDonald, Mrs May added: "Briefings have been offered to all members of the House, not just privy counsellors, subsequent to action.
"Before action, briefing was only offered to opposition leaders."
In a hot-tempered debate Jeremy Corbyn demanded a War Powers Act to give MPs a vote on future military action.
He said the "convention since the Iraq War" has been to ask Parliament before committing troops to battle.
He added: "The people put us here to take decisions on their behalf.
"Enshrining the right of elected MPs to decide on matter sod peace and war is an essential vital development.
"17 countries have the rights of parliament to approve military action enshrined in their own laws
"It should escape no one that the general public want to see an increased role of parliament."
But Theresa May told MPs: "In the post-Iraq era it is natural for people to ask questions.
"But we have an obligation to protect the safety and security of our sources.
"We must maintain secrecy if our intelligence is to be effective now and in the future."
She added: "There are situations, not least major deployments like the Iraq War, where the scale of the military build-up requires the movement of military assets over weeks and where it is absolutely right and appropriate for Parliament to debate military action in advance.
"But that does not mean it is always appropriate.
"It therefore cannot and should not be codified into parliamentary right to debate every possible overseas mission in advance."
There were several angry clashes during the debate.
Tory MPs jeered as they demanded to know how Jeremy Corbyn would have voted - and he replied: "This is a debate about process."
He added: "I made my very clear my concerns about this strike... it's pretty obvious what my view of it was."
Mr Corbyn rebuked another MP telling them to “take a break and read a bit of the Chilcot Report."
Tory MP Andrew Bridgen suggested Mr Corbyn would not have committed troops to "retake the Isle of Wight".
And in heated scenes Speaker John Bercow told heckling Tory Alec Shelbrooke to "be quiet" and "stop it".
Theresa May meanwhile claimed Jeremy Corbyn has "consistently opposed" military action in the past.
And there were cheers and jeers as Labour's Karen Lee claimed MPs have "less say in foreign policy in this country than President Trump."
The Prime Minister replied: "Let no one in this House be in any doubt.
"Neither I, nor this Government, take instructions from any president or any other national government.
"When we act, we act in what we believe to be the national interest, that is our only concern."
Meanwhile Tory former Foreign Secretary William Hague said it was a "mistake" to let Parliament vote on military action in Syria in 2013.
The statement was a major shift from Lord Hague, who only in 2011 said parliament WOULD be given powers to veto military action.
Lord Hague was backed in his new verdict by Tory MP Nick Boles, who said: "We made a fundamental error. We should never have held that vote."