The favourite to become the next leader of UKIP is in serious condition in hospital after allegedly being ‘punched by a colleague’.

The UK Indpendence Party is this week gearing up for its second leadership election of the year, after leader Diane James stood down after 18 days.

Former UKIP leader Nigel Farage, who stood down earlier this year, is currently serving as interim leader.

The party’s Member of European Parliament Steven Woolfe had been considered the favourite to take over the party.

However, after a shocking incident in a UKIP meeting today in Strasbourg, he has been rushed to hospital with a potential brain injury.

A statement says: “Steven Woolfe was taken suddenly ill in the European Parliament building in Strasbourg this morning. He has been taken to hospital in the city and is undergoing tests.”

However, the Telegraph reports that sources within the party allege that Mr Woolfe was “punched by a UKIP colleague” following an altercation at a meeting of the party’s MEPs.

Nigel Farage confirmed that an “altercation” had taken place.

He said: “I deeply regret that following an altercation that took place at a meeting of MEPs this morning that Steven Woolfe subsequently collapsed and was taken to hospital. His condition is serious.”

Other runners and riders for the election, including Suzanne Evans and former Farage adviser Raheem Kassam, have reacted with shock.

UKIP Parliamentary Spokesperson Suzanne Evans said: “Shocked to hear Steven Woolfe has apparently collapsed in the European Parliament in Strasbourg. Wishing him well for a speedy recovery.”

Kassam tweeted: “I really hope Steven Woolfe is okay. Plz send him your best wishes.

“I have cancelled my appearance on BBC Daily Politics out of respect to Steven Woolfe who is currently being treated after collapsing.”

UKIP is the last major UK-wide party with anti-LGBT policy stances. Leaked internal vetting documents earlier this year showed the party had knowingly let a number of people flagged as having homophobic views stand as candidates.