The frontrunner in Ukip's leadership contest to replace Nigel Farage could be kept off the ballot because of a "technical error" with the submission of his nomination papers. North West MEP Steven Woolfe filed the application and the required £5,000 deposit to the party just 25 minutes before the deadline closed yesterday afternoon (31 July).

But a spokesman for Woolfe claimed "technical problems" on the party's system meant the application did no go through until 17 minutes after the 12pm deadline.

"Woolfe was speaking to party officials responsible for handling the application process throughout this time and right up to the deadline," the spokesman added. "He informed them that he was having technical problems. These problems were finally resolved and the paperwork submitted."

Woolfe, who also serves as Ukip's migration spokesman, argued that he is still a candidate in the leadership contest.

Ukip's ruling body, the National Executive Committee (NEC), is expected to meet tomorrow to decide if Woolfe can remain in the race after missing the crucial deadline. Woolfe's spokesman had not responded to a request for comment from IBTimes UK on why he left his submission so close to the deadline.

The development comes after the former barrister faced claims that he was ineligible to stand in the contest because he had reportedly allowed his membership to lapse. Ukip rules mean leadership hopefuls have to be a member of the party for at least two consecutive years.

Woolfe told IBTimes UK that he had received confirmation from Ukip's outgoing chairman, Steve Crowther, that he has been a "member of good standing" for the past two years and blamed the party's "poor infrastructure systems" for apparently failing to recognise his payments.

"As far as I'm concerned, I am a member and I am capable of standing until they prove to me that I'm not, which is going to be almost impossible for them to do so," he added.

If he is kept on the ballot, Woolfe is expected to face West Midlands MEP Bill Etheridge, North East MEP Jonathan Arnott, Ramsey councillor Lisa Duffy and Ukip NEC member Liz Jones. A new leader will be announced on 15 September.

A Ukip spokesman said: "Nominations have been received. Vetting will take place over the next few days. It must be understood that Ukip cannot comment on the process."