BRITAIN is set to join a coalition of Western and Arab nations in mounting airstrikes against the "vile threat" of Islamic State terrorists in Iraq after Ed Miliband made clear Labour would support the UK Government in a Commons vote tomorrow.

The party leader's backing for the Coalition position means a green light for RAF planes to be involved in bombing runs as early as this weekend. MPs have been recalled to Parliament to discuss the matter. Britain is already providing arms and surveillance support to Kurdish forces.

Last night it was reported that up to five British jihadists, including a teenager from Brighton, are believed to have been killed in Syria during US airstrikes. Ibraham Kamara, 19, is thought to have been fighting for al Nusra, an affiliate group of al Qaeda, in the war-torn country. A Foreign Office spokeswoman said it was aware of the reports.

Prime Minister David Cameron, who a year ago suffered the humiliation of a Commons defeat over whether to launch airstrikes on Syria following the Bashar al Assad regime's use of chemical attacks on its own citizens, said: "What we are doing is legal, it is right, it does not involve British troops on the ground. As ever with our country, when we are threatened in this way we should not turn away from what needs to be done."

He was granted a recall of Parliament by the Speaker following a request for military help from the newly elected government in Baghdad. Such a request is regarded by British officials as crucial to providing the legal basis for any military action under international law. Any plan to extend UK involvement in airstrikes to Syria would require a further Commons debate and vote.

After an emergency Shadow Cabinet meeting at Labour's party conference, Ed Miliband confirmed the party would support the Government on airstrikes in Iraq. He said: "We cannot turn away from the threat of ISIL [Islamic State]."