Relations between David Cameron and Ed Miliband are at their most hostile ever in the wake of the Government's Commons defeat over Syria. Labour aides accused the Prime Minister of making "foreign policy by tweet" and blamed him for Britain's withdrawal from military action.
In turn, No 10 sources claimed the Labour leader, below, was "putting party before country" and had "flip-flopped" over his party's position on military retaliation for the chemical weapons attack in Ghouta, Damascus, on 21 August.
The two party leaders blame each other for the failure of Britain to remain at the table in any intervention against the Assad regime. "It is David Cameron's fault where we are at the end of the week," a senior Labour source said.
Despite the shock defeat on Thursday, Mr Cameron is understood to have pledged his personal support to President Obama in a robust response to President Assad. In a 15-minute phone call on Friday night, the US President told Mr Cameron he respected the PM's approach after Parliament voted against any response to the Ghouta atrocity.
The phone call followed a barbecue at Chequers hosted by Mr Cameron for 30 of his backbenchers. Although it was planned six weeks ago, the event was an opportunity for the PM to heal what some see as a gaping rift between Downing Street and Tory MPs. Two of Thursday's rebels were at the barbecue, and a source said that Mr Cameron wanted to listen to their views on Syria. While the atmosphere was civil, some Tory MPs are seeing the defeat as an opportunity to cast around for an alternative leader. Mr Cameron faces a difficult party conference in Manchester later this month.
Ten government members were absent from the vote, and some ministers who backed the motion did so with deep unhappiness. One said he was very cautious about British involvement, adding "all options are shit, but we need to make sure we have a proper plan".
As recriminations flew around Westminster, a senior Labour source accused Mr Cameron of a "stubborn refusal to accept the importance of the UN weapons inspectors". Pointing out that Mr Cameron had tweeted the latest steps on Syria on Wednesday, the Labour source said: "We would suggest that foreign policy by tweet shows a sign of a Prime Minister rushing into a conflict on a political timetable not of his choosing."
No 10 responded with fury, accusing the Labour leader of "flip-flopping". Downing Street claimed that in talks last Tuesday Mr Miliband said his "bottom line" was putting a resolution to the UN Security Council – but by Wednesday he was insisting that there needed to be a second vote after weapons inspectors had reported.
The source said: "The only conclusion the PM could come to was that Ed Miliband was playing politics. Under pressure from his own party he kept changing his position. Say what you like about David Cameron's parliamentary tactics, he took a principled decision, having seen images of dead children and people frothing at the mouth." An aide to Mr Miliband insisted he had made clear all along the importance of UN weapons inspectors' findings.