A U.K. Independence Party legislator who was hospitalized after an altercation at the European Parliament has announced he is leaving the party that played a crucial role in the country's decision to leave the European Union.

Steven Woolfe, who had been a leadership contender, said he has made a police complaint about the Oct. 6 altercation.

Woolfe has accused fellow UKIP legislator Mike Hookem of punching him during the argument. Hookem denies the allegation.

Woolfe suffered a seizure a short time after the incident and was hospitalized for several days.

The party said Monday it will announce its new leader Nov. 28. Nigel Farage is serving as interim leader.

UKIP played an important role in the June referendum taking Britain out of the European Union.