LONDON, England (AFP) - British Prime Minister David Cameron's authority was being questioned on Saturday following his stunning parliamentary defeat on action against the Syrian regime.
Newspapers said his leadership of the Conservative Party had been shaken, with thirty rebels from his own side contributing to Thursday's defeat in the House of Commons.
In the most humiliating defeat of Mr Cameron's three years in power, lawmakers voted to reject his call for British involvement in military strikes aimed at punishing the Syrian regime for alleged chemical weapons use.
US President Barack Obama now risks suffering the same fate, after he announced on Saturday that he would ask Congress to authorise military action.
In London, more than a thousand anti-war protesters gathered at Trafalgar Square to proclaim "victory" after lawmakers saw off Mr Cameron's hopes of joining US-led strikes against Syria.
The British prime minister is considering his next moves as he tries to limit the fall-out from Thursday's sorry episode.
Several newspapers said Mr Cameron would likely reshuffle his cabinet in a bid to boost his authority. Ten government members missed the key vote - including some who failed to return from holiday and two who did not hear the warning bell.
The Daily Telegraph said at least five ministers faced the sack over what it called the "Syria shambles".
One unnamed minister was quoted in The Guardian as saying: "The veil has been ripped away and we know there are a number of Tory MPs who are willing to do serious damage to David Cameron".
A senior Conservative added: "It's a bit like being present after a massive explosion. There is broken glass and dust everywhere and it will take time for the dust to settle." The Independent said Mr Cameron had failed in his reading of the public mood, while the debacle had exposed once more the rift in the Conservative Party between the government and restive backbenchers.
A rump of Conservative MPs have never reconciled themselves to Mr Cameron leading the centre-right party into coalition with the smaller, centrist Liberal Democrats.
Mr Cameron is "humbled at home and weakened abroad", The Independent said.
The opposition Labour leader Ed Miliband did not emerge unscathed from the fall-out either.
Mr Cameron accommodated Miliband with a series of concessions to his motion, in a bid to send a strong message from Britain's parliament on the use of chemical weapons - only to see Mr Miliband change tack and lead every Labour MP who voted to reject the motion.
The Daily Mail said Mr Miliband had "repaid Mr Cameron's straight-dealing with a display of wriggling political opportunism that should fill the nation with distaste".
It added: "Where Mr Cameron's future is concerned, yes, he has been humbled. But the damage is far from terminal. Indeed, a little humility may yet make him a better and stronger prime minister, if it teaches him to listen."
The Sun said that while Mr Cameron had made a "monumental blunder" in failing to shore up Conservative support, "the real villain is Ed Miliband", who decided that "playing politics was more important than the lives of gassed children".
"By voting to rule out even the possibility of responding to a crime against humanity, the House of Commons shamed our great nation," it added.
MPs had forgotten the lesson of Britain's 1930s appeasement of Nazi Germany, the top-selling tabloid said.
Syrian President Bashar al-Assad "will see that our condemnations are meaningless. He now knows we will only ever shout at him".
Doctor Andrew Blick, a lecturer in politics and contemporary history at King's College London university, said some Conservatives exploited a chance to rebel against Mr Cameron.
However, for many lawmakers, the shadow of parliament's vote to back the 2003 invasion of Iraq loomed large.
"For some people this is like a re-run of Iraq - only this time around they didn't want to make the same mistake that was made last time," he told AFP.