Labour’s internal split over renewing the Trident nuclear programme was reinforced yesterday as the shadow foreign secretary, Emily Thornberry, urged her party to abstain from a vote in parliament on its renewal this week, while leadership challenger Owen Smith said he would back the government and Jeremy Corbyn said he would vote against.
The House of Commons will spend much of today debating the government’s decision to replace the fleet of nuclear-armed submarines. The vote was decided earlier this month by David Cameron as a way to put the decision “beyond doubt”.
However, the debate has threatened to exacerbate divisions within Labour. The leader, Jeremy Corbyn, opposes renewing Trident but many of his MPs take a similar view to Smith, and official Labour policy is to back the renewal. The party is in the midst of an internal review of its nuclear weapons policy.
Thornberry, who was shadow defence secretary until she was promoted following mass resignations from Labour’s front bench, said the vote was “shameful” and “a political game”, when parliament could have been discussing the Nice attacks and the coup in Turkey.
“There is nothing new in this debate – a vote in principle was agreed in 2007 – and nothing whatsoever will happen as a result,” she wrote in the Guardian. “It is being held simply to sow further divisions inside the Labour party. The Tories know that those with strongly-held principles on either side of this debate will vote with their consciences, and the media will turn that into a fresh Labour crisis.” 
Labour MPs, says Thornberry, “should treat this government and this vote with the contempt they deserve”.
“There are clear principled and practical reasons why Labour MPs should refuse to vote with the government today,” she said. “They propose an open-ended commitment to maintain Britain’s current nuclear capability ‘for as long as the global security situation demands’. Such a vague, indefinite commitment precludes any possibility of Britain ever stepping down the nuclear ladder and contributing to global multilateral disarmament.”
In the piece, co-authored with Labour MP Clive Lewis, she adds: “We will be abstaining from this ludicrous exercise, and getting on with the real job instead.”
Labour whips are expected to grant MPs a free vote because of the ongoing policy review.
But Smith, the former shadow pensions secretary who is, with the former shadow business secretary Angela Eagle, challenging Corbyn for the party leadership, said yesterday he would back Trident renewal.
Speaking on BBC1’s The Andrew Marr Show, Smith said that while he had once been a member of CND (Campaign for Nuclear Disarmament) he now argued for more general disarmament.
“I’m a multilateralist and I believe that the world has actually got more volatile and more insecure over the last few years,” he said. Smith said he had changed his mind 15 years earlier, and now believed the UK’s nuclear capability should be kept “until we can use it as a bargaining chip to get everybody to get rid of their nuclear weapons”.
Asked whether he would order a nuclear strike as prime minister, which Corbyn said he would not, Smith replied: “You’ve got to be prepared to say yes to that. It was a mistake of Jeremy to say that (he would not). I understand, it’s a terrible thought for anybody.  I think the world has got more volatile – we’ve got to stick with what we’ve got and renew it, if that’s the advice of the security services. And it’s awful that we’ve got to do that, but I’m afraid it’s true.”