UKIP leadership contender Steven Woolfe is in hospital in a "serious" condition following an "altercation" at a party meeting Thursday morning.
A party spokesperson said in a statement that Woolfe had been taken to hospital and was undergoing tests, but did not provide further details.
Interim party leader Nigel Farage 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."
Woolfe announced Wednesday that he would contest the party leadership following the resignation of Diane James, who had served just 18 days after winning the leadership election.
Raheem Kassam, a fellow leadership contender, said he was cancelling a BBC interview out of respect. Suzanne Evans, who is thought to be considering a bid, used Twitter to send Woolfe her best wishes.
"Shocked to hear Steven Woolfe has apparently collapsed in the European Parliament in Strasbourg. Wishing him well for a speedy recovery," Evans said.
