British Prime Minister David Cameron has said airstrikes against Islamic State militants in Syria would be in Britain's "national interest".
While making a case in the House of Commons for military action, the prime minister denied claims that it would make Britain a bigger target for terror attacks, BBC reported.
He told lawmakers that Britain was already a target for the IS and the only way to deal with that was to "take action" now.
Britain could not "outsource our security to allies" and it had to stand by France, he added.
A Commons vote was expected within weeks on whether to authorise airstrikes.
The prime minister urged lawmakers to back military action as he sets out a "comprehensive strategy" to tackle IS.
He published his response to a recent Foreign Affairs committee report on airstrikes ahead of the speech, saying: "The threats to our interests and to our people are such that we cannot afford to stand aside and not to act."
Cameron was expected to tell lawmakers: "Decisions to use force are not to be taken lightly. It is right that Parliament, on behalf of the people, asks difficult questions and holds the government to account."
Cameron, whose statement comes just under a fortnight since the terror attacks in Paris which claimed 129 lives, will need to convince enough lawmakers from other parties to back his case in order to offset any Conservative rebels.
Lawmakers rejected strikes against Syrian government forces in a 2013 vote, but have since authorised action against IS in Iraq.
The government argues it was "illogical" to restrict action to Iraq as IS does not recognise the border between the countries.
It has said it will call a vote on targeting the group, which it refers to as ISIL, only when it is sure to win.
