Nicola Sturgeon has urged Labour to make a decision on Trident amid rumours that the UK Government could call for an early vote on its renewal.

The issue of Trident has led to deep divisions within Labour which were fuelled last week by leader Jeremy Corbyn's suggestion that the UK could retain Trident but put the submarines to sea without warheads.

Former cabinet minister Dame Margaret Beckett said the suggestion was a "way of exploring other ideas" as the party tears itself apart over its future policy, but warned that the internal turmoil will be immaterial as the main decision on renewal is set to be taken this year.

She told BBC Radio 4's Today programme: "Some of this conversation, frankly, is going to be irrelevant by the time of the next election because major decisions about Trident will have been made."

However, Ms Sturgeon has now said Labour must make a decision on the nuclear missle submarines and claims that there are rumours that the UK Government could call for an early vote on its renewal.

The SNP is opposed to Trident and have made it clear that the party will not back the renewal of it.

The UK Government have refused to rule out holding a vote on the renewal of the nuclear missile submarines before the Holyrood elections in May.

In November, UK Government sources said that the so-called 'maingate' decision on the controversial issue was expected to be made before the elections on May 5.

Mr Corbyn, who is fiercely opposed to replacing Trident, has previously said that Labour activists will be given a 'big say' in whether the party continues to back its renewal.

Union chief Sir Paul Kenny made it clear earlier this month that GMB would not go 'quetly into the night' if Mr Corbyn tried to change Labour's policy to oppose Trident.

David Cameron said there was a "comic element" to Mr Corbyn's proposals that nuclear submarines could be sent to sea without missiles but insisted Trident renewal was the ultimate insurance policy.

In response to suggestions in Prime Minister's Questions that Labour's policy had been inspired by the Beatles song Yellow Submarine and Mr Corbyn needed Help, Mr Cameron said: "There is a comic element to sending submarines to sea without missiles but, in fact, it is absolutely serious because the deterrent has been on a cross-party basis an absolutely key part of our defence and making sure we have got the ultimate insurance policy, which we support on this side and we should vote on in this House.

"All I can say, when it comes to Beatles songs, I suspect the leader of the Opposition prefers Back In The USSR."