Labour shadow cabinet warned not to oppose Jeremy Corbyn over Syria
Labour's top team has been warned not to oppose Jeremy Corbyn over military action in Syria after the party leader said he could not support RAF air strikes against Islamic State (IS) extremists.
Diane Abbott - one of Mr Corbyn's few allies in the shadow cabinet - said Labour MPs who backed David Cameron over air strikes would put themselves at odds with grassroots party members.
Her intervention came as the rift between Mr Corbyn and the majority of his shadow cabinet spilled out into the open after the Labour leader said the Prime Minister had failed to make a "convincing case" for further military intervention against IS.
His comments were in sharp contrast to those of shadow foreign secretary Hilary Benn, who said Mr Cameron had made "compelling arguments" when he set out his case for extending air strikes against IS into Syria in a Commons statement.
After a 90-minute meeting of the shadow cabinet to discuss their response failed to reach an agreement, shadow ministers will gather again on Monday in an attempt to thrash out an common position.
Ms Abbott, the shadow international development secretary, warned that those who supported air strikes - said to be the overwhelming majority of the shadow cabinet - could expect to come under pressure from local activists when they return to their constituencies at the weekend.
"I am sure that people will go home, they will talk to their friends, they will talk to their constituents and we'll make the final decision on Monday. I am confident that it will be the right decision," she told Channel 4 News.
She added: "He (Mr Corbyn) is the one with the electoral mandate, he appoints the shadow cabinet - not the other way round. I know what views party members will take if MPs ignore the views of the people at the grassroots and try and take this issue to the brink."
Ms Abbott later told Sky News: "You cannot have a shadow cabinet voting down the leader of the Labour Party who has just been elected with the biggest mandate in history."
Mr Corbyn - who did not express a view one way or the other in his response to Mr Cameron in the Commons - angered some Labour MPs by then issuing a letter setting out his opposition in a move seen by some as an attempt to appeal over their heads to the grassroots.
He said the key issue was whether attacking IS - also referred to as Isil or Isis - in Syria would strengthen or undermine Britain's national security.
"I do not believe that the Prime Minister today made a convincing case that extending UK bombing to Syria would meet that crucial test," he said.
"In particular, the Prime Minister did not set out a coherent strategy, co-ordinated through the United Nations, for the defeat of Isis."
The divisions in the Labour ranks complicate Mr Cameron's calculations as to whether he has got the numbers to win a Commons vote on extending air strikes against IS - currently restricted to Iraq - into Syria.
The Prime Minister has repeatedly said he will not seek the support of the House unless he is certain of winning as defeat would hand a propaganda victory to the extremists.
But with some Conservative MPs still opposed to further military intervention, he is likely to need the support of a significant number of Labour MPs to ensure he gets the outcome he wants.
In his statement, Mr Cameron acknowledged that air strikes alone would not defeat IS, but said action was needed to counter the "very direct threat" which they posed to the UK.
"We do face a fundamental threat to our security," he said.
"We have to hit these terrorists in their heartlands right now and we must not shirk our responsibility for security or hand it to others," he told MPs.
Several MPs questioned his claim that there were 70,000 troops on the ground in Syria aligned to moderate groups.
Downing Street said that the figure had been provided by the Joint Intelligence Committee (JIC) - the UK's senior intelligence body.