A former Labour defence minister and ex-head of the Navy has threatened to resign his party’s whip if Jeremy Corbyn reverses its policy on Trident.

Lord West, who served as security minister in Gordon Brown’s government, said that he did not like nuclear weapons but he "feared" the UK needed them.

The row erupted on the eve of a speech by the Labour leader to the Unite trade union's Scottish conference in Glasgow.

The head of Unite, Len McCluskey, is expected to use his address to the same event to warn that any changes must not be railroaded through without the input of his members.

In an apparent attempt to defuse the growing row Labour also sidelined close Corbyn ally Ken Livingstone, who earlier this week suggested a decision on Trident would be rushed through.

The former London mayor said that his party's defence review could produce its findings on the nuclear deterrent before Easter.

But Emily Thornberry, the new unilateralist shadow defence secretary, announced that the inquiry would continue to accept submissions up until April 30, weeks after Mr Livingstone suggested it could present its conclusions.

Labour sources also said that Mr Livingstone would have no formal role in the review, just days after he described it as a "lot of work for me and Emily".

Ms Thornberry said that she hoped to produce an interim report by June, which could then be considered at Labour's annual conference in the autumn.

Conservative sources said the revised timetable meant that the Commons could vote on Trident before Labour has made a decision on its position.

A number of high-profile Labour MPs have warned that the Tories, who have a working majority of 16, will drive through the renewal of the deterrent no matter what Labour does.

Three current Shadow Cabinet members, Lucy Powell, Owen Smith and Lord Falconer, have refused to rule out quitting their frontbench positions if Labour opposes replacing the ageing system on the Clyde.

Lord West, the former First Sea Lord, said: “I think I would give up the Labour whip if that happened.

“What I hope is there is going to be proper debate and discussion and what I have found over the years is people who are anti-Trident, when they hear all of the arguments and see all of the issues they realise actually that although none of us like nuclear weapons - it’s trite to say I don’t like nuclear weapons; who on earth likes nuclear weapons? - but we need them pragmatically, I fear.”

Ms Thornberry called for submission from Labour members, defence specialists, non-governmental organisations and the Armed Forces.

She said that she was "extremely sceptical" about Trident and would ask some "very difficult questions" about its future.

The review will look at whether or not renewal would affect security and “the values that guide our foreign and defence policy".

Labour said that the “safety and security of the British people must always be our first priority" but added that Britain "has a responsibility to promote a more peaceful world".

Mr McCluskey said that his members would be reassured by the new timeline.

Paul Kenny, the leader of the GMB union, hit out at some Labour politicians, calling on them to take a vow of silence over Trident's future until the review has concluded.

"It is not helpful for the confidence of the people affected if senior politicians who claim to have major influence over the outcome make announcements on what their position is," he said.

"The review has to honestly deal with the issue that is of great concern to GMB and others about what is going to happen to the tens of thousands of jobs that directly depend on the current Trident programme and the successor programme.

"The unions are not going to surrender responsibility for defending members' jobs.”