Robert Kilroy-Silk is facing a leadership challenge six months after setting up his new party Veritas.
Mr Kilroy-Silk lost his bid to win the Erewash seat
The MEP had quit the UK Independence Party after failing to become leader.
Now Veritas member Ken Wharton wants to run against the ex-chatshow host saying the party is being mismanaged. He wants to run as soon as a contest is allowed.
A party spokesman said it would allow a challenge if the party members wished. But he said Mr Kilroy-Silk was more concerned with the Cheadle by-election.
The spokesman added: "As a truly democratic party, Veritas will allow a leadership contest every year if the party members wish."
Discontented members have set up the Veritas Members' Association pledging to "put the truth back into Veritas".
They want to change the way the party is run, and make it more accountable to the membership.
They claim 10 of Veritas' general election candidates have already tendered their resignations from the party.
Mr Wharton argues that Veritas members are "not being looked after".
The 47-year-old, who served in the Navy and is now unemployed, said he planned to run as soon as possible.
At the general election Mr Kilroy-Silk failed in his bid to win the Erewash seat, slipping to fourth place behind the three major parties.
Mr Kilroy-Silk lost to incumbent Labour MP Elizabeth Blackman, who won re-election with a decreased majority.
In the Cheadle by-election, Stockport Borough Council leader Mark Hunter will run on 14 July for the Lib Dems against Tory Stephen Day and Labour's Mark Miller.
Veritas' candidate is Leslie Leggett, and John Allman of Alliance for Change - Suffering Little Children is running.