British war planes could be bombing Islamic State in Syria within 72 hours under plans being drawn up by Downing Street.

Senior No 10 sources said that a Commons vote was now most likely to take place on 2 December – but this will happen only if the Prime Minister is sure he has the support of a clear majority of MPs. The Government also does not want a vote to clash with the Oldham West by-election on Thursday.

David Cameron is understood to be concerned that this will give the impression that he is playing politics with issues of war and peace. However, any vote before 2 November is unlikely because of Labour’s continuing divisions on air strikes, which will not be resolved until at least the late on 30 November.

At 1pm on 30 November, Jeremy Corbyn will chair a crunch meeting of the Shadow Cabinet to decide the party’s position. Then at 6pm he will face a possibly mutinous weekly meeting of Labour MPs in Parliament.