DAVID Cameron has requested the recall of Parliament to debate the UK's response to the Iraqi government's request for support against Isil.

MPs will return to Westminster on Friday for a vote which could clear the way for RAF planes to join the US, France and a number of Arab states in bombarding IS positions as early as the weekend.

Mr Cameron is desperate to avoid a repeat of last year's damaging Commons defeat over air strikes against Syria and will be looking for Labour support in the vote.

Mr Cameron said: "I have requested that Parliament be recalled to debate the UK response to the Iraqi government's request for support against Isil. The Speaker has accepted my request to recall Parliament on Friday.

A Downing Street spokesman said: "The Speaker has agreed to the Prime Minister's request to recall Parliament this Friday to debate the UK's response to the request from the Iraqi government for air strikes to support operations against Isil in Iraq. The Commons will meet on Friday for a debate on a substantive motion. The Prime Minister will open the debate and the Deputy Prime Minister will close the debate. The Prime Minister has called a meeting of the Cabinet tomorrow at 1pm."

As the shadow cabinet met in Manchester at the end of the Labour Party conference to discuss its position, leader Ed Miliband said he would consider any request from the Prime Minister "very seriously".

"Isil is a threat that cannot be ignored," he told the BBC. "If a proposition comes forward for military action by the UK, obviously we are open to it and will look at it."

Mr Cameron was this evening meeting his Iraqi counterpart Haider Abadi for talks which are likely to see Baghdad request the UK to join the US-led military action against IS.

A formal request from the Iraqi government would give the Prime Minister - currently attending the United Nations General Assembly meeting in New York - the legal cover he believes is needed to go ahead.

Meanwhile, US president Barack Obama issued a call for the world to come together to tackle the threat posed by IS and "dismantle this network of death".

Speaking to the General Assembly, Mr Obama said that IS understood only "the language of force" and called on those who have joined up to fight with the group - believed to include several hundred Britons - to "leave the battlefield while they can".

Defence Secretary Michael Fallon said the conditions were "falling into place" for the RAF to join the strikes against IS - also referred to as Isis or Isil (Islamic State of Iraq and Levant).

"The conditions that the Prime Minister originally set are now falling into place," he told BBC News during a visit to Afghanistan.

"This is an international effort - you've seen other countries come in alongside the United States. This week for the first time we have seen other Arab countries involved in air strikes."

Mr Fallon made clear that MPs would be asked only to support air strikes against IS, and that - unlike the US - the Government would not be seeking to extend them into Syria where there has been no comparable request from the regime of president Bashar Assad.

With the US - which extended its military action against IS into Syria for the first time yesterday - having already mounted around 190 air strikes in northern Iraq since August, Britain's involvement is more important politically than militarily.

Ahead of his meeting with Mr Abadi in New York, Mr Cameron became the first UK prime minister to hold talks with an Iranian president since the revolution of 1979.

As Mr Cameron sought to enlist Hassan Rouhani's backing for the international coalition against IS, the Iranian president posted a picture of the two of them shaking hands on his Twitter feed.

The Prime Minister made no comment to waiting reporters after the hour-long meeting, but was overheard telling an aide: "A little bit of history done."

Speaking to the General Assembly, Mr Obama condemned atrocities against women and religious minorities in IS-controlled areas and described the beheading of hostages including British aid worker David Haines as "the most horrific crimes imaginable".

The US president said: "No God condones this terror. No grievance justifies these actions. There can be no reasoning - no negotiation - with this brand of evil.

"The only language understood by killers like this is the language of force. So the United States of America will work with a broad coalition to dismantle this network of death."

Mr Obama said the US would not send troops to "occupy foreign lands", but will "support Iraqis and Syrians fighting to reclaim their communities". The US was not acting alone, but had assembled a coalition of more than 40 nations, including Arab states.

He added: "Today, I ask the world to join in this effort. Those who have joined Isil should leave the battlefield while they can. Those who continue to fight for a hateful cause will find they are increasingly alone. For we will not succumb to threats; and we will demonstrate that the future belongs to those who build - not those who destroy."

Mr Cameron was also backing a UN resolution tabled by the US, which would impose global travel bans on foreign fighters planning to join conflicts overseas.

The move, pushed personally by Mr Obama at a Security Council meeting attended by Mr Cameron, requires UN member states to update national laws to stem the flow of foreign fighters, including by withholding passports and freezing assets.

Last night the wife of British aid worker Alan Henning issued an appeal to IS to release her husband after she was sent an audio message of him pleading for his life.

Barbara Henning called for the militant group to "open their hearts and minds" and said she had been told that a Sharia court had found her husband innocent of being a spy.

"I implore Islamic State to abide by the decisions of their own justice system. Please release Alan," she said.

Deputy Prime Minister Nick Clegg confirmed that the Liberal Democrats would be supporting the Government motion.

"There are many people across the country who see what this medieval murderous organisation does, slaughtering people regardless of their ethnicity or their religion; an organisation which is actively plotting to do us harm in this country," he said.

"I think most people across the country want the British Government to play our part in ridding the world of this vile threat."