Jeremy Corbyn, the Labour party leader, is to accept a new role as vice-president of the Campaign for Nuclear Disarmament as figures show a sharp upturn in support for the organisation.

Corbyn, who is currently vice-chair of CND, will accept the position during a two-day conference in London on Saturday. His acceptance of the role underlines his opposition to nuclear weapons in the face of criticism from within the shadow cabinet.

The Labour leader has long opposed nuclear weapons and said last month that he would tell defence chiefs never to use the Trident nuclear weapons system if he became prime minister.

His appointment highlights the conflict between Corbyn and senior members of the shadow cabinet on the issue of nuclear weapons. The shadow foreign secretary, Hilary Benn, believes that Britain needs a “continuous at-sea deterrent”. He and several other shadow ministers including the deputy leader, Tom Watson, believe that supporting the renewal of Trident is essential to convince voters that Labour can be trusted with the nation’s security.

Kate Hudson, general secretary of the CND, welcomed the move and said the conference would be the most important gathering of anti-nuclear activists in a generation.

“[The] conference takes place at a moment when, for the first time in a generation, the opportunity not to replace Trident collides with a massive popular upsurge against the criminal waste and sheer anachronism of nuclear weapons,” she said.

“Austerity has led many more to question the need to spend £100bn on replacing a nuclear weapons system that doesn’t tackle the real security threats we face. Terrorism, climate change, pandemics and cyberwarfare require a fresh approach.”

CND has seen a big increase in support since Corbyn launched his election campaign. The organisation was attracting about 30 new members a month in June but now has a sign-up rate of more than 200 a month.

A spokesman said the support was still gathering pace, with more than 100 new members joining in the last seven days and thousands of non-paying supporters signing up since the summer.

Corbyn’s longstanding opposition to nuclear weapons has provoked criticism from within the parliamentary Labour party since he became leader last month. After he said he would not authorise the use of nuclear weapons if he were prime minister, the shadow defence secretary, Maria Eagle, described his comments as “unhelpful”. Two leading unions also expressed their opposition to Corbyn’s anti-nuclear stance.

But his supporters say the rise in support for the CND shows how Corbyn’s victory is energising politics beyond Westminster, from anti-nuclear to anti-austerity campaigns.

The former London mayor Ken Livingstone said: “After the years of the Thatcher/Blair tyranny, I think people realise that they can have an influence in politics again; it is worth getting involved, whether it is environmental groups, CND or the Labour party,” he said.

Corbyn is due to speak at a closed session of the CND conference on Saturday. Senior figures from the Green party, and the Scottish National party’s defence spokesman, Brendan O’Hara, will also attend the event.

Hudson said the growing party political support, combined with the increase in new members and supporters, would make it hard for the government to prevent a genuine debate over Trident.

“In Scotland, a majority voted for the anti-Trident SNP; the new leader of the Labour party firmly opposes nuclear weapons and is facilitating a national policy debate in his own party. The Lib Dems will oppose like-for-like replacement. The Green surge represents further opposition ... The government will find it increasingly hard to claim it is acting in the national interest if it cannot garner cross-party support for Trident and when it is at odds with growing public opposition.”

The UK has four Trident ballistic missile submarines, and a final decision about whether to replace them is due to be taken in 2016. Previously both the Labour and Tory leaderships were committed to replacing the fleet, a project that is likely to cost well over £100bn over its 30-year lifespan. But now Corbyn has committed Labour to a review of its Trident policy, to be headed by Eagle.



Hudson welcomed Labour’s stance and said the anti-nuclear campaign would continue to gather momentum in the coming months. “Our own organisation has experienced its own surge in membership and we’re preparing for a major national Stop Trident demo ahead of the parliamentary decision in 2016,” she said.