David Cameron has started to present his case for the UK to join the air strikes on Islamic State targets in Syria.

The prime minister began the debate against vociferous calls for an apology from Labour, the Liberal Democrats, and the SNP, after it was reported that he called on Conservative MPs to vote for war and not stand with “Jeremy Corbyn and a bunch of terrorist sympathisers”.

The Labour leader has previously argued that Cameron has failed to show that bombing IS will work in pushing them back and degrading their attacking capabilities.

After a week of crises and divisions within the Labour Party over the case for joining air strikes on Syria, Corbyn announced that Labour MPs would have a free vote on the issue.

Around 90 Labour MPs are expected t vote with the government and support the case for war, but at least 110 MPs from six different parties, including all SNP MPs, have already signed up to an amendment seeking to block air strikes.

A 10-hour Commons debate will conclude with a vote on whether the UK should expand it air strikes on IS targets from Iraq to also include Syria.