Another contender to become UKIP leader has pulled out of the contest – leaving three in the race.
Peter Whittle said he would back Paul Nuttall as “a leader who knows the party inside out and who can command the loyalty” of all members.
Former deputy leader Mr Nuttall, former deputy chairwoman Suzanne Evans and ex- soldier John Rees-Evans remain in the contest, to be decided on 28 November.
Raheem Kassam also withdrew from the contest on Monday.
In a message on Facebook, Mr Whittle said Thursday’s High Court ruling, which found that the government could not trigger Article 50 – the formal process of leaving the EU – without consulting Parliament, showed that “the battle to ensure that the Leave vote in the referendum is respected is far from over and UKIP is needed more than ever”.
Mr Whittle, the party’s culture spokesman and a former London mayoral candidate, added that the “sheer breadth of Paul’s political experience, his dedication to the values of the party and the obvious affection in which he is held by members make him the person who is best placed to take us forward”.
Nigel Farage is back as interim leader after his successor Diane James quit just 18 days into the job.
Mr Kassam, a former aide to Mr Farage, had endorsed Mr Whittle after himself pulling out of the race.
Three left in UKIP race as Peter Whittle withdraws}