The Campaign for Nuclear Disarmament has been riven by allegations of entryism by the hard left after the group's chairwoman was unexpectedly ousted.
Carol Naughton, CND's leader for the past two years, lost her post by one vote to Kate Hudson, the organisation's vice-chair, who was allegedly backed by a group of Trotskyite supporters.
Ms Naughton's supporters say that days before last weekend's CND conference, about 25 sympathisers of the Trotskyite group Socialist Action and the Socialist Workers Party joined CND and applied to become delegates. Ms Hudson won by 167 votes to 166.
Bruce Kent, the former CND chairman, claimed the election was "ethically rigged" and predicted it would lead to calls for reform of the organisation's voting system. "I'm sure there's going to be a major fightback," he said.
The row has rekindled a long-running feud between CND's moderate old guard and left-wing activists in the Stop the War Coalition (SWC), which co-organised the anti-Iraq war demonstrations in London earlier this year with CND and the Muslim Association of Britain.
Earlier this year, Ms Naughton clashed with senior SWC figures over tactics and the inclusion of Palestinian issues in the protests.
Ms Hudson came to prominence, and won praise from all wings of CND, after overseeing its involvement in the anti-war demonstrations by working closely with SWC officials from the SWP and Socialist Action. CND's high anti-war profile saw its membership jump to over 32,000.
But some activists fear her election will lead to CND, which has historically been non-party political, becoming involved in a wider anti-US, left-wing agenda.
Ms Hudson denied the allegations. She said CND staff had investigated the entryism claims and had found many of the new members who voted were long-standing CND supporters. "My personal political affiliations have got nothing to do with my work and my commitment to CND," she said. "I have never brought my political affiliations into CND in any way."
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