Senior Ukip officials are expected to meet today to discuss leader Henry Bolton's future amid reports Nigel Farage is plotting a return to frontline British politics.
Ukip's national executive committee (NEC) is said to be planning to hold a vote of confidence in their leader during a special meeting on Sunday, one week after the party was rocked by revelations his girlfriend had sent racist messages.
The party leader has faced a volley of calls to resign since his now former partner was revealed to have made highly offensive comments about Meghan Markle and black people.
The outcry over messages sent by 25-year-old model Jo Marney, in which she said Prince Harry's fiancee was a "dumb little commoner" whose mixed-race background would "taint" the royal family, saw a senior Ukip MEP quit in protest.
Mr Bolton, who has resisted calls to step down, is due to make a series of television appearances on Sunday.
Several newspapers have reported that Mr Farage is in talks to launch a rival to Ukip if Mr Bolton steps down and the party loses its fourth leader in 18 months.
Ukip chairman Paul Oakden is said to have emailed party members on Saturday saying the NEC does not have powers to remove Mr Bolton and a new leader can only be chosen through a ballot of members.
In the message shared by activists online Mr Oakden called for unity, adding: "Let's all come together to sort this out and put this party back on the road."
Mr Farage, who stepped down as Ukip leader in 2016, has been vocal in recent weeks about his fears about Brexit, accusing Leave campaigners of failing to adequately press the case for Britain's departure after the referendum.
He has previously said he would have "no choice" but to return to frontline politics if it appeared the Brexit he campaigned for is under threat.
The Sunday Times reports that Mr Farage has spoken to friends and held talks with multimillionaire former Ukip donor Arron Banks about launching a new pro-Brexit movement.
The newspaper says Mr Farage has been invited to be the group's president, while Mr Banks, an insurance tycoon, will be its chairman.
According to the Mail on Sunday Ms Marney, whose party membership was suspended as her comments about Ms Markle were published, resigned from Ukip on Saturday after being presented with more evidence of offensive messages.
Ukip Treasury spokesman Jonathan Arnott left the party in protest at Mr Bolton's leadership on Friday.
He said he had "forlorn hope" when Mr Bolton was elected leader in September but it has become "abundantly clear" he is not the right person for the job.