Paul Nuttall is the odds-on favourite to succeed Nigel Farage and become the next leader of Ukip on Monday (28 November). The former deputy leader is expected to beat former deputy chair Suzanne Evans and former parliamentary candidate John Rees-Evans.
Nuttall, 39, has billed himself as the unity candidate throughout the election after prolonged in-fighting within Ukip. The latest leadership election was triggered after Diane James MEP quit the post in October. She had spent just 18 days in the job.
James later resigned from the party altogether, following in the footsteps of Steven Woolfe MEP, who warned that the Eurosceptic party was in a "death spiral".
Nuttall, who represents the North West of England in the European Parliament and hails from Merseyside, plans to target Labour seats if he is elected.
"We have this fantastic opportunity, which we've never had before to this extent, to move into Labour working-class communities and mop up votes," he told The Sunday Telegraph.
"I think in some of these communities we can replace the Labour party in the next five years and become the patriotic party of the working people."
He added: "You've got a Labour party whose leader refuses to sing the national anthem, whose shadow foreign secretary sneers at the flag, whose shadow chancellor says nice things about the IRA. That isn't going to chime well with working-class people."
Ukip's sole MP Douglas Carswell, who defected to the party from the Conservatives in 2014, said he was excited by the leadership election because it would give the party a chance to "press the reset button".
But Ukip's financial and electoral future remains unclear. With the Brexit vote, its raison d'etre has been fulfilled, while major donor Arron Banks has openly talked about turning his Leave.EU group into an anti-establishment political movement.
The leadership election announcement is expected around 11.15 GMT.