UKIP’s leader Gerard Batten has announced he will stand down on 2 June to trigger a leadership contest.
The MEP was elected into the top job unopposed in April 2018 and promised to resign after 12 months to allow a full raft of candidates to run.
Party sources confirmed that his term of office had been slightly extended so he could oversee both the local and European elections as leader.
Mr Batten said he had not decided whether to stand again.
A UKIP spokesman said: “Mr Batten is fulfilling a promise to step down and call a leadership election approximately one year after becoming full party leader.”
Mr Batten became UKIP’s interim leader in February 2018 – and the fourth person to lead UKIP in 19 months.
Nigel Farage stepped down after the EU referendum, but resumed his post when his successor Diane James quit after less than a month at the helm.
Paul Nuttall then took the job, but resigned when UKIP performed badly in the 2017 general election.
Steve Crowther was then acting leader until Henry Bolton was elected in September.
But Mr Bolton was ousted after a row in which his girlfriend, Jo Marney, faced allegations she had sent racist messages about the Duchess of Sussex.
Mr Batten has been criticised for the direction he has taken UKIP, especially after naming former English Defence League leader Tommy Robinson – whose real name is Stephen Yaxley-Lennon – as an adviser.
It led to a raft of resignations from the party, including from Mr Farage, who accused the UKIP leader of being “pretty obsessed with the issue of Islam”.
But Mr Batten said he had saved the party “from oblivion”, and that Tommy Robinson was “a good person to have on side”.
In last week’s local elections, UKIP lost 145 councillors.