Jeremy Corbyn has emailed Labour Party members asking them what their party should do on Syria, as the party splits ahead of the crucial vote on whether to bomb the country.
Corbyn remains opposed to such a vote but his Shadow Foreign Secretary Hilary Benn has said there is a "compelling" case for bombing Islamic State in the civil war-ravaged country.
The big question ahead of the vote is whether Labour will whip its MPs to vote against David Cameron's plan or allow a free vote.
On Friday evening, the Labour leader wrote to party members saying he did not believe Cameron had made "a convincing case" for the bombing but asked members what the party should do.
"There could not be a more important matter than whether British forces are sent to war," Corbyn wrote.
"When I was elected I said I wanted Labour to become a more inclusive and democratic party.
"So I am writing to consult you on what you think Britain should do. Should Parliament vote to authorise the bombing of Syria?"
The email in full:
On Thursday David Cameron set out his case in the House of Commons for a UK bombing campaign in Syria.
We have all been horrified by the despicable attacks in Paris and are determined to see ISIS defeated.
The issue now is whether what the Prime Minister is proposing strengthens, or undermines, our national security.
I put a series of questions in response to the Prime Minister's statement, raising concerns about his case that are on the minds of many in the country.
There could not be a more important matter than whether British forces are sent to war.
As early as next week, MPs could be asked to vote on extending UK bombing to Syria.
I do not believe that the Prime Minister made a convincing case that British air strikes on Syria would strengthen our national security or reduce the threat from ISIS.
When I was elected I said I wanted Labour to become a more inclusive and democratic party.
So I am writing to consult you on what you think Britain should do. Should Parliament vote to authorise the bombing of Syria?
Let me know your views, if you are able to, by the start of next week.
Yours,
Jeremy Corbyn MP
Leader of the Labour Party
Former Home Secretary Jacqui Smith is one of those who has responded, though she called it "dubious" as Corbyn has "already made his mind up".
Others noted the contradiction of asking your membership what to do when he had already made his views clear.
But HuffPost UK's Paul Waugh said Corbyn was likely expecting the members to be against intervention in Syria, bolstering his own position.
The BBC's Allegra Stratton said the email appeared to be an attempt to "undercut" the views of those in his Shadow Cabinet he disagreed with.
Francois Hollande has called on MPs to back military intervention in Syria in the wake of the Paris attacks that left 130 dead.
The French President thanked Britain for the support it has shown his country following the atrocity and said he hoped that Parliament would now back the case for air strikes.
He told a press conference at the Commonwealth Heads of Government Meeting (Chogm) in Malta: "I do hope that the House of Commons will be able to meet the request of Prime Minister Cameron."
The socialist president's comments will be seen as a major appeal to Labour MPs wavering over whether to back action to defeat Islamic State in Syria.