Ukip leadership favourite Steven Woolfe is recovering in hospital after collapsing following an alleged punch-up with a fellow Member of the European Parliament.
Woolfe was embroiled in an "altercation" with another Ukip politician - said to be Mike Hookem - at a "clear the air" meeting this morning.
The married father-of-one - who was marking his 49th birthday today - reportedly fell over at one point during the scuffle and banged his head.
Despite walking away from the fight, Woolfe then collapsed and had a fit around two hours later - at around 11.20am UK time (11.20pm NZ time) - and was rushed to hospital.
At one point his injuries were thought to be life-threatening, but in a statement issued from his hospital bed this afternoon, Woolfe said: "The CT scan has shown that there is no blood clot in the brain.
"At the moment I am feeling brighter, happier, and smiling as ever."
He went on: "As a precaution, I am being kept in overnight awaiting secondary tests to make sure everything is fine.
"I would like everyone to know that the parliamentary staff, the Ukip MEPs with me and hospital staff have been brilliant. Their care has been exceptional.
"I am sitting up, and said to be looking well. The only consequence at the moment is a bit of numbness on the left hand side of my face."
Sources claimed the row was over Woolfe's admission that he had considered defecting to the Tories after being "enthused" by Theresa May's new direction.
After being told he was a "joke" during the meeting, Woolfe apparently took off his jacket and challenged Hookem to "settle this outside".
A party source said: "Words were said, and suddenly the pair had taken their jackets off and went outside to have a fight.
"Woolfe fell over at one stage during the fight and banged his head on some bars. It is thought he was only punched once. He then suffered a fit."
A spokeswoman for Hookem insisted it had been a "verbal altercation" and denied that he had punched Woolfe. "Mike did not touch him," she said.
Images published by ITV News this afternoon appear to show Woolfe sprawled unconscious on the floor two hours later while someone tries to help him.
Interim leader Nigel Farage, an ally of Woolfe, said in a statement: "I deeply regret that following an altercation that took place at a meeting of Ukip MEPs this morning that Steven Woolfe subsequently collapsed and was taken to hospital. His condition is serious."
The fight took place on the Passerelle, the wrought iron bridge which crosses the Rhine river in front of the European Parliament.
Woolfe is said to have suffered a second fit later on, before losing all feeling in one half of his body.
The shocking development comes after the Eurosceptic party was plunged into chaos following the shock resignation of Diane James from its top job.