UKIP leadership favourite Steven Woolfe is in a serious condition after an 'altercation' in EU Parliament

Steven Woolfe, the overwhelming favourite to succeed Diane James as UK Independence Party leader, is in a "serious condition" after reportedly being punched by a colleague.

Woolfe, the party's Manchester-born migration spokesperson, collapsed after a routine meeting with fellow UKIP MEPs in European Parliament on Thursday.

Woolfe was suddenly taken ill after being involved in an "altercation" during the meeting, according to Sky News.

This story is developing...