A majority of party members backed a motion of no confidence in UKIP Leader Henry Bolton, who had faced growing pressure to resign since a newspaper in mid-January published the messages Jo Marney wrote about Meghan Markle, Prince Harry's fiancee.
Party members will gather in Birmingham on Saturday for an emergency general meeting to decide whether to endorse a vote of no confidence in Mr Bolton by UKIP's ruling body.
Gerard Batten will take over as Ukip's interim leader, the party announced.
UKIP, the party credited with the strongest support for Brexit in the 2016 vote on Britain's departure from the European Union, must now elect its fifth leader in less than two years.
The Ukip leader, who has defended his decision not to stand down, saying that the party can not handle another leadership contest and that its constitution needs a complete overhaul, claimed he was the victim of rivals "stirring the pot".
"Secondly, there were a small number of individuals within the party, failed leadership contenders, who saw an opportunity in me leaving my wife to go in for the kill - they're stirring the pot... if they were truly dedicated to the party and their country and not to their own they would have stayed at their posts".
Mr Bolton - who told Sky News he was "quietly confident" ahead of the meeting - had been clinging on to the leadership after a revolt by several senior party figures over his relationship with model Jo Marney.
Speaking after the result, Mr Bolton said he had not finished in politics and was "batting around" various options for the future. "There's probably been nothing like that since the Profumo affair or Diana and Dodi".
He declined to elaborate and did not answer when asked if one was to set up an alternative party.
The party's former chief revealed his fears for UKIP's future on the eve of a crunch meeting, at which the fate of current leader Henry Bolton will be decided.
"It may be too late to save UKIP, but you never know".
On Saturday, Feb. 17, UKIP members will decide on whether or not Bolton will continue to run the office.
The revelations sparked fury from Ukip bosses and led to calls for him to quit as party leader.
He continued: "The basis structures of the party organisation are disappearing; branches are closing and numerous sitting councillors in the forthcoming elections wish to run as independents".
In an earlier address to the around 1,400 members, Bolton claimed his opponents were "the enemy within" the party.