By William James
LONDON (Reuters) - Britain's opposition Labour Party said on Monday its lawmakers could vote according to their consciences on air strikes against militants in Syria, a move which may hand Prime Minister David Cameron the parliamentary majority he needs.
Cameron believes it is time to join other Western powers in bombing Islamic State, saying Britain could not subcontract its security to other countries after the militant group claimed responsibility for killing 130 people in Paris this month.
But he must persuade some skeptical members in his own ruling Conservative Party and others in Labour, which is deeply divided on the subject after its leader, veteran anti-war campaigner, Jeremy Corbyn said he was opposed to the strikes.
By allowing the so-called 'free vote' - breaking with a tradition for party leaders to instruct lawmakers on how to vote on major decisions, Corbyn has moved to quell a rebellion in Labour, which had threatened to engulf his two-month leadership.
"Today's Shadow Cabinet agreed to back Jeremy Corbyn's recommendation of a free vote on the government's proposal to authorize UK bombing in Syria," the Labour Party said, referring to leading lawmakers who shadow the government's portfolios.
It said they were also backing Corbyn's call for the government to allow a two-day debate on launching air strikes, much longer than usual because it was "such a crucial decision".
The foreign minister, Philip Hammond, said he was now confident the government would secure a parliamentary majority -- avoiding a repeat of the damaging defeat parliament handed Cameron in 2013, when parliament voted against launching air strikes against Syrian President Bashar al-Assad.
"During the course of today there has been significant progress in the task of building a coalition in parliament in favor of air strikes in Syria and ensuring that when it comes to a vote that coalition is able to find its voice," he said, according to the Press Association news agency.
A senior Labour source said Corbyn would argue that Cameron had yet to meet the conditions set out by Labour at its annual conference earlier this year, including the provision of "clear and unambiguous" United Nations support for air strikes.
"There will be a majority of Labour MPs (lawmakers) who will vote against this, even under free vote conditions. If he (Cameron) was looking for ... consensus behind the backing for this war, he certainly is not going to get it," the source said.
Earlier, the party said three-quarters of its members opposed bombing in Syria, according to a sample of responses the party received over the weekend.
While many in Labour fear more air strikes will bring more instability to the region, some of the party's leading members said they could not vote against them, arguing they were necessary to ensure Britain's security.
The source said senior Labour lawmakers, including foreign affairs spokesman Hilary Benn, would be able to argue the case for military action, and against their party leader, without being forced to resign as would usually be the case.
(additional reporting and writing by Elizabeth Piper, editing by Stephen Addison and Richard Balmforth)