Nigel Farage could be banned from the European parliament for his failure to declare almost half a million pounds in gifts from Brexiteer donor Arron Banks.
The Brexit Party leader has been set a 24 hour deadline to attend the European parliament to explain his failure to declare the gifts from Banks - giving him up until 5pm on Wednesday.
The Telegraph reports he was issued a summons to a formal hearing after a meeting of the parliament's code of conduct committee.
It is believed that Farage may be found guilty of a breach of the rules even if he does appear to defend himself, but could mitigate his punishment if he promises to update his register.
He could be banned for up to a month for breaking the rules, which includes having his access badge withdrawn.
Such a ban would mean the leader of the Brexit Party would not be able to lead his MEPs when it first sits again.
Millionaire Brexit backer Banks is alleged to have given Farage as much as £450,000 in kind following the EU referendum, which included a chauffeur-driven car, rent and bills on a £4.4m Chelsea home, and trips to the United States to meet right-wing politicians.
The investigation was sparked following the Channel 4 News investigation - who were subsequently banned for a short period from Brexit Party events during the European election campaign.
Commenting at the time, Banks said: "Channel 4's attempts to smear myself and Nigel come at a time when the Brexit Party is riding high in the polls, so it should come as no surprise to anyone."
In a statement, Farage said: "What is this but an EU kangaroo court where I am given 24 hours notice about allegations picked up from press stories.
"I will not be attending at such short notice. And if they try to bar me from the building, who else gives voice to the thousands of people who voted for me? Is this democracy EU style?
"I did not receive any private money for political purposes. This committee would better spend its time investigating the waste of public money by well-known MEPs."
Recently an old video was uncovered which showed Nigel Farage boasting about how MEPs can milk the system.
Last year his salary was docked by half for misspending EU funds intended to staff his office.