British MPs to vote on Syria air strikes after marathon debate

British MPs will decide later today whether to back UK air strikes in Syria against militants from so-called Islamic State.

A 10-hour House of Commons debate will culminate in a vote on whether the UK should join the US, France, Russia and others bombing targets in Raqqa, the group's stronghold, and other areas.

UK Prime Minister David Cameron says IS is a threat to Britain's security.

Labour leader Jeremy Corbyn opposes bombing but has given MPs a free vote amid divisions within his own ranks.

With up to 50 Labour MPs likely to back the government - and both the Democratic Unionist Party and the Liberal Democrats backing action - Cameron is expected to win parliamentary approval for the UK to intervene militarily in the four-year conflict in Syria.

However, at least 110 MPs from six different parties - including the SNP, which opposes action - have already signed up to an amendment seeking to block air strikes.

The government motion would authorise air strikes "exclusively" against Islamic State - also known as Isis, Isil or Daesh - in Syria.

The debate is due to begin at 11:30 GMT - with a vote expected at around 22:00 GMT.