The party passed a no confidence motion in Henry Bolton on Sunday
Two senior UKIP figures have quit their roles and called on the leader of the British party to resign.
Deputy leader Margot Parker and immigration spokesman John Bickley stood down following Sunday's vote of no confidence in Henry Bolton by UKIP's ruling body.
The emergency action by the party's National Executive Committee (NEC) followed a row over the 54-year-old's relationship with a 25-year-old model.
Ms Parker claimed Mr Bolton's "personal life took over the job he was elected to do".
She told BBC Radio Northampton: "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."
Mr Bickley later resigned his immigration brief on LBC Radio.
Mr Bolton (54) faced growing calls to quit over his relationship with model Jo Marney.
Mr Bolton ended the "romantic element" of their relationship last week, when it emerged party activist Ms Marney had sent offensive messages about Prince Harry's fiancee Meghan Markle.
She was also reported to have sent separate messages making jokes about child sexual abuse.
The news comes less than four months since he was elected.
Following Sunday's meeting, party chairman Paul Oakden said: "In an emergency meeting of the UKIP National Executive today, a discussion took place on recent press coverage of the party leader, Henry Bolton.
"Having heard a statement from Mr Bolton, the NEC asked a number of questions pertaining to that coverage.
"At the conclusion of that discussion, the committee took the decision to hold a vote of no confidence in the leadership of Henry Bolton.
"The vote was carried unanimously, with the exception of the leader.
"This decision will automatically trigger an EGM of the party, to allow the membership of UKIP the democratic opportunity to decide to endorse or reject that vote of no confidence."
This meeting will be held within the next month - unless Mr Bolton resigns first.