Arron Banks, who used to be one of the UK Independence Party’s biggest donors, is demanding that Ukip pays him £200,000 for call centre and other services he provided for free.
Mr Banks, who donated £1million to Ukip before the last general election, has submitted the invoice after he fell out with senior figures in the party and his membership lapsed.
Mr Banks said he had decided to invoice the party for the cost of providing call centre and membership services after the party had effectively suspended him.
He said that, given Ukip had “effectively” suspended his membership, “why on earth am I going to donate the service for free. I don’t think so. So – yes – there is a bill in the post for the thick end of £200,000."
Ukip confirmed that Mr Banks had asked for some of his donations to be paid back but insisted that he had not had his membership suspended.
A spokesman said: “Since Arron Banks first became involved with Ukip, before the last General Election, he has been a generous donor.
“All the support he has given UKIP has been on that basis and not on a supplier/client one.
"We don't understand why he now claims his generous donations were something different.”
Mr Banks claimed last week that he believed he was suspended because he suggested the “current leadership couldn't knock the skin off a rice pudding”.
Ukip countered that Mr Banks’ membership had “lapsed earlier in the year”.