Video report by ITV News Political Correspondent Carl Dinnen
Ukip leadership frontrunner Steven Woolfe has resigned from the party just weeks after collapsing in the EU parliament following an altercation with a fellow MEP.
Woolfe said he has "come to the conclusion that UKIP is ungovernable without Nigel Farage leading it and the referendum cause to unite it".
Woolfe, who joined Ukip six years ago, said the party is "riddled with infighting, proxy wars between rival camps and is run by an NEC that is not fit for purpose".
Mr Woolfe was involved in an altercation with fellow Ukip MEP Mike Hookem in Strasbourg on October 6.
Mr Woolfe reiterated in his resignation statement that he "received a blow" from Mr Hookem and said he has made a police complaint.
He added: "The events at the meeting in Strasbourg led to me later being treated by doctors for two seizures, partial paralysis and loss of feeling in my face and body."
Mr Hookem "absolutely" denies being responsible for Mr Woolfe's injuries and claims he acted in self-defence during a "scuffle".
Mr Woolfe said in a statement: "I believe that a strong UKIP would hold this government's feet to the fire and make sure it delivers a clean Brexit. However, I have come to the conclusion that UKIP is ungovernable without Nigel Farage leading it and the referendum cause to unite it.
The way I was treated by members of my own party during the Summer’s leadership campaign and the events that have led up to today have all contributed to me coming to this conclusion. The party is riddled with infighting, proxy wars between rival camps and is run by an NEC that is not fit for purpose.
He said he intends to sit an independent MEP in the European Parliament.
He added: "I will continue to represent my constituents in the European Parliament until the UK's exit from the EU in 2019. I will champion the values I hold dear - those of freedom, democracy and an independent United Kingdom."
Woolfe tweeted his full statement: