Video report by ITV News Political Correspondent Libby Wiener
Ukip leadership hopeful Steven Woolfe has been expelled from the race.
The MEP's candidacy was judged ineligible after he missed the deadline for submitting paperwork by 17 minutes.
But, Woolfe's leadership campaign might not be over.
A source close to Steven Woolfe has told ITV News that they are confident they have the support to call an emergency meeting and disband the NEC.
The failed leadership hopeful said he is "extremely disappointed" to have been excluded from the contest and accused the party's ruling committee of being "not fit for purpose".
Three members of Ukip's ruling National Executive Committee, Michael McGough, Victoria Ayling and MEP Raymond Finch, announced they were quitting the body over the "deliberate obstruction" of Mr Woolfe's nomination.
Woolfe - who had previously admitted to failing to reveal a drink-driving ban when he stood to be a police commissioner in 2012 - said:
I am extremely disappointed by the Ukip NEC decision to exclude me from the party's leadership election.
The NEC's decision has left the future of the party in the balance.
Speaking to BBC Radio 4's World At One programme, MIchael McGough said: "To me this is a fight for survival.
"If we don't get this right, we don't get a competent leader who's comfortable with the media, the party could be finished."
The Ukip leadership race was triggered by Nigel Farage's resignation in July, saying he has "done his bit".
The former leader has previously attacked the NEC members, describing them as "among the lowest grade of people I have ever met".
The party announced that six candidates would be running for leader.
They are: Jonathan Arnott, Phillip Broughton, Lisa Duffy, Bill Etheridge, Diane James and Elizabeth Jones.
You can see profiles on all the hopefuls here.