The British National party's sole representative on the London assembly has resigned the party whip amid speculation that the BNP is on the verge of unravelling.
Richard Barnbrook, who lost his Barking and Dagenham council seat earlier this year, is understood to have taken the decision in protest at the increasing tensions within the organisation, which has seen a series of spats between senior figures in the last few weeks.
Barnbrook told the assembly he had resigned the BNP whip because of several serious allegations circulating within the party and has called for an "independent internal investigation" to be carried out before he returns to the fold. He is understood to remain a BNP member.
Earlier this week Nick Griffin, the BNP leader, saw off a leadership challenge from Barnbrook and three others. However, critics say he only managed to hold on to power by carrying out a widespread purge of internal opponents.
Tensions have been growing since May's general election when the BNP failed to make its promised breakthrough, and the council elections where all but two of its 28 sitting councillors standing for re-election were beaten.
"The BNP seems to be unravelling," said Nick Lowles from Searchlight. "Griffin has sacked or suspended over 30 critics and Barnbrook's decision seems to suggest the party is on the verge of full-scale revolt."