UKIP leader Henry Bolton is facing a wave of resignations from key positions as pressure mounts on him to quit.
The local government, education, trade and immigration spokesmen have all resigned, along with the deputy leader and assistant deputy leader.
It comes after the national executive committee backed a vote of no confidence in him.
Mr Bolton has faced repeated calls to quit over offensive texts sent by his ex-girlfriend.
He has said he plans to carry on as leader, saying another leadership contest would be divisive and a costly distraction.
He has also said he has ended the “romantic element” of his relationship with girlfriend Jo Marney after she sent texts saying Prince Harry’s fiancee Meghan Markle would “taint” the Royal Family, leading to accusations of racism.
In his resignation letter as trade spokesman William Dartmouth, a South West England MEP, told Mr Bolton his position was “untenable”.
“When you became leader you said that you would make the party successful,” he said.
“If you still feel that way then you should resign forthwith.”
UKIP’s leadership changes
- Nigel Farage: UKIP’s long-serving leader announced his resignation on 4 July 2016, saying his “political ambition has been achieved” by the Brexit vote
- Diane James: Lasted less than three weeks after being elected in September 2016
- Nigel Farage: Returned as interim leader in October 2016
- Paul Nuttall: Elected on 28 November 2016, but quit the following June after UKIP’s general election collapse
- Henry Bolton: Elected on 29 September. Is facing resignations and a vote of no confidence
Deputy leader Margot Parker, who is an East Midlands MEP, said Mr Bolton’s “personal life took over the job he was elected to do”.
She added: “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.”
Party members will now be given a vote on whether Mr Bolton, who became leader of UKIP in September 2017, should remain in post.
UKIP chairman Paul Oakden said Mr Bolton was “disappointed” by the NEC’s decision but understood “that the party has a process to go through”.
“Henry was offered the opportunity to resign but he has made clear that he feels he is the right man to lead the party forward,” he added, after a three-hour emergency meeting on Sunday to decide his future.
UKIP, which has long campaigned to leave the EU, came top in the 2014 European elections and got the third largest vote share in the 2015 general election with 12.6% – but this plummeted to 1.8% in June.
If Mr Bolton were to step down it would leave UKIP seeking its fifth leader in 18 months.
The committee does not have the power to remove the former army officer – that can only be done by a vote of the party’s membership.
The 53-year-old party leader, who left his wife prior to his relationship with Ms Marney, 25, became public, said: “I don’t believe I have done anything wrong.
“My own personal life, it’s a little bit of a mess at the moment. I need to sort that out, of course.”
UKIP said in a statement that, after a discussion of “recent press coverage” of the leader, “the committee took the decision to hold a vote of no confidence in the leadership of Henry Bolton”.
It added: “The vote was carried unanimously, with the exception of the leader.”
Under UKIP rules, an emergency general meeting must be staged within 28 days to endorse or reject the no confidence vote.
Members will be told about when and where it will be held in the next 10 days.
Neil Hamilton, the party’s leader in Wales, said: “He should now resign from UKIP immediately so we can get on with rebuilding the leadership of the pro-Brexit party without further distraction.
“If he forces us to hold an EGM, he will only humiliate himself further.”
Gerard Batten, UKIP MEP for London, said Mr Bolton’s position was “untenable” and that the controversy was “damaging” UKIP, and he offered to step in as interim leader.