UKIP donor Arron Banks has suggested he could stand against the party's only MP Douglas Carswell at the next election.
The two have been at loggerheads over UKIP's future direction and strategy.
Mr Banks has called for the Clacton MP and a "Tory cabal" to be expelled - with ex-leader Nigel Farage also saying it was time for Mr Carswell "to go".
Mr Carswell, who defected from the Tories to UKIP in 2014 and won the Essex seat at the 2015 election, said Mr Banks's plans were "news to him".
The BBC understands party leader Paul Nuttall has asked his chairman Paul Oakden to meet Mr Carswell on Tuesday to "discuss the situation" amid growing questions about his future in the party.
Mr Carswell and Mr Banks have been engaged in a long-running feud. The latest development comes amid claims that Mr Carswell resisted attempts by senior UKIP figures to secure a knighthood for former leader Nigel Farage.
The Daily Telegraph reported that in an email the MP suggested Mr Farage should settle instead for an OBE for "services to headline writers".
On Monday, the MP, who has denied trying to block a knighthood for Mr Farage, alluded to the row when he tweeted "knight night".
Following UKIP leader Paul Nuttall's failure to win the Stoke-on-Trent Central by-election last week, Mr Banks has said the party is at a "crossroads" and has offered to become party chairman in order to bring about a "total rebrand".
He has said Mr Farage, who stepped down last year and has since spent much of his time in the United States, should be "re-engaged".
Mr Banks has described Mr Carswell, whose relationship with Mr Farage is also strained, as a "terrible individual who has done his best to destroy UKIP".
Mr Banks' office said he intended to stand in Clacton, the Essex seat which Mr Carswell won with a 3,437 majority in 2015. It is not clear whether he will seek the UKIP nomination himself or will stand as an independent.
Mr Farage has claimed the party's only MP has been "totally disconnected" from UKIP since February 2015 and it was time for him to sever his links entirely.
"From the date of the result of the general election, he has actively been working against UKIP," Mr Farage wrote about Mr Carswell in the Daily Telegraph.
"I think there is little future for UKIP with him staying inside this party. The time for him to go is now," he added.
Mr Farage told the BBC: "If Paul [Nuttall] is constantly contradicted and dragged in the wrong direction by our one MP, that's not where he should be."
MEP Bill Etheridge has also said Mr Carswell should lose the party whip as he was "not compatible with what UKIP is trying to achieve". He told Radio 5 live that Mr Carswell should "look elsewhere" for his political future.
He told Radio 4's World at One the situation was "not a party at war it is one man... who has gone out of his way to subvert the party's leadership".
"I'm not suggesting that Douglas isn't a good MP he just doesn't have the UKIP principles at heart," Mr Etheridge said.
But UKIP Welsh Assembly member Mark Reckless said Mr Carswell should stay, saying "we have got to learn from him" as he won a Parliamentary election.
Mr Carswell, who has urged the party to project a more positive image and tone down its rhetoric on immigration, has warmer relations with Mr Nuttall and several of his key advisers.
Current UKIP chairman, Paul Oakden, said after the Stoke result that it might be years before his party can pick up another seat via a by-election.
Mr Banks criticised Mr Nuttall's tactics in the Stoke campaign, saying he wrongly adopted a "red UKIP" strategy, copying Labour policies on the NHS.
The businessman has said UKIP needs to become more professional if it is to make further headway, saying that as chairman he would oversee a new membership drive, and install a new team of "trained professional agents" to focus on target seats.
Unless this happened, he has suggested he could turn his back on the party.