Henry Bolton’s grip on the leadership of Ukip is under severe strain as a series of senior figures quit over his refusal to resign.
Deputy leader Margot Parker and assistant deputy leader Mike Hookem were among those who said they were unable to serve in his top team.
The resignations came after Ukip’s ruling national executive committee (NEC) backed a motion of no confidence in Mr Bolton on Sunday following the disclosure that his girlfriend had sent racist messages about Meghan Markle.
Mr Bolton has faced a stream of calls to resign since the highly offensive messages sent by Jo Marney, 25, were published by the Mail on Sunday.
She said: “It would be quicker and cleaner if he came to the conclusion he could go sooner rather than later.
“This is taking time away from doing the job. This puts the party in a limbo situation.”
“Ukip is now in the preposterous situation of the leader’s private life being of more interest than the party,” Mr Hookem said in his resignation letter to Mr Bolton.
Mr Bickley told LBC radio: “I believe he really needs to go and focus on sorting out his personal life, and get away from politics.
“If, by a number of people resigning and showing that they no longer wish to work for him, that helps him make that decision, then fine.”
In his letter of resignation, Lord Dartmouth said: “The NEC as well as colleagues on the London and Welsh Assemblies and fellow MEPs have all urged you to stand down as party leader with immediate effect.
“Your position is untenable. I am unable to serve under you.”
Party members will now decide Mr Bolton’s fate in a vote at an emergency meeting in February.
Meanwhile, Ukip chairman Paul Oakden suggested that former leader Nigel Farage could take on a greater role in the party.
He told BBC Radio 4’s Today programme: “I think everybody would like him to have a greater role in Ukip. Whether that’s as leader or not, I don’t know if I would subject Nigel to that.”