The chairman of UKIP is to step down after overseeing next Saturday’s vote on the future of leader Henry Bolton.
Paul Oakden said he would leave his post for personal reasons and his exit was “absolutely unconnected” to the vote or recent infighting in the party.
UKIP members will decide whether to back or sack Mr Bolton following criticisms of his private life.
Mr Oakden said he had “absolute faith” in members to do what was right to protect the party’s long-term future.
Mr Bolton lost a vote of confidence by the party’s National Executive Committee last month after it emerged that his partner, Jo Marney, had sent offensive texts about Meghan Markle, who is to marry Prince Harry in May.
Mr Bolton’s political fate will now be decided by the party’s members at an extraordinary general meeting in Birmingham.
Speaking on Sunday, Mr Bolton suggested he was still in a relationship with Ms Marney and rejected suggestions his leadership was over, despite a wave of resignations from his frontbench team in recent weeks.
In a letter to UKIP supporters, Mr Oakden said he had intended to step down last autumn after the party’s annual conference but had agreed to stay on for a short time at Mr Bolton’s request after his election.
While now was the “right time” to go, he insisted it had nothing to do with next Saturday’s vote, insisting that he was required to remain “impartial” in the leadership process and would continue to serve the party.
“I have made this decision irrespective of the outcome of the EGM and I’m announcing it now to ensure that it remains absolutely unconnected to whatever democratic decision the membership may take on Saturday,” he said.
Mr Bolton, UKIP’s fourth party leader in about 18 months, has suggested he will overhaul the NEC if he wins Saturday’s vote, as part of efforts to professionalise the party.