David Cameron has promised to set out a "comprehensive" strategy for tackling Islamic State (IS) on Thursday that will include British air strikes on the terrorists' bases in Syria.
The Prime Minister confirmed he would be coming to parliament to "make the case" for wider military action after holding talks with French president Francois Hollande in the wake of the attacks on Paris.
Unveiling the Strategic Defence and Security Review (SDSR) to MPs, Mr Cameron said IS - also known as Isil, Isis or Daesh - was "not some remote problem thousands of miles away".
"It has already taken the lives of British hostages and carried out the worst attack against British people since 7/7 on the beaches of Tunisia, to say nothing of the seven terrorist plots right here in Britain that have been foiled by our security services over the past year," he said.
"On Thursday I will come to this House and make a further statement responding personally to the Foreign Affairs Committee. I will make the case for Britain to join our international allies in going after Isil in their headquarters in Syria, not just in Iraq.
"I will explain how such action would be one element of a comprehensive and long term strategy to defeat Isil in parallel with major international effort to bring an end to the war in Syria."