Nigel Farage's bid to turn a growing financial controversy into a political showdown ran into immediate resistance Tuesday after Britain's major political parties refused to contest the parliamentary by-election triggered by his resignation, denying the Reform UK leader the head-to-head campaign he had sought, Politico reported.

Farage announced he was stepping down as the member of Parliament for Clacton while simultaneously declaring he would seek reelection in the by-election, casting the race as a referendum on what he called attacks from the political establishment over his finances.

"This will be a people versus the establishment by-election," Farage said during a press conference in London. "It's a chance to stick two fingers up to the entire establishment."

But within hours, the country's major political parties rejected the challenge.

The governing Labour Party, the opposition Conservatives, the Liberal Democrats, the Green Party and Restore Britain all said they would not field candidates, accusing Farage of staging a political spectacle to divert attention from ethics investigations into his financial disclosures.

Conservative leader Kemi Badenoch said Farage appeared unable to withstand scrutiny.

"What I saw was a man who is cracking under the pressure," Badenoch told Politico. She later confirmed the Conservatives would not contest the seat.

Liberal Democrat leader Ed Davey urged other parties to deny Farage the platform he was seeking.

"If this by-election does go ahead now, we are calling on all parties to stand aside and refuse to give oxygen to Farage's vanity project," Davey said.

A Labour Party spokesperson said Farage was "engulfed in a sleaze scandal" and accused him of trying to "change the subject."

The coordinated boycott leaves Farage, who won Clacton by more than 8,400 votes in the 2024 general election, facing the prospect of running largely unopposed while still using the campaign to argue that Britain's political establishment is aligned against him.

Farage's announcement follows weeks of scrutiny over his financial arrangements. He is under investigation by Parliamentary Commissioner for Standards Daniel Greenberg over whether he violated House of Commons rules by failing to declare a £5 million donation from cryptocurrency investor Christopher Harborne.

Farage has denied any wrongdoing, maintaining he was not required to disclose the donation because it was received before he became the member of Parliament for Clacton and was made in a personal capacity to help fund private security.

On Tuesday, Farage also disclosed he is facing a separate investigation over allegations that he failed to declare gifts and donations from cryptocurrency entrepreneur George Cottrell. He again denied breaking parliamentary rules.

Farage said publication of a photograph of his daughter's home by a national newspaper was "the final straw" that prompted his resignation and decision to seek a renewed mandate from voters.

He also defended wealthy individuals supporting politicians.

"We absolutely need successful people from all walks of life — but particularly from business and industry," Farage said. "We need them not just in Parliament; we need them in government if we are even going to have half a chance of turning around the dire economic state this country."

Despite resigning his seat, the parliamentary investigations are expected to continue.

Matthew England of the Hansard Society said House of Commons rules allow ethics investigations to proceed even after a member resigns, meaning Farage could still face sanctions if he is reelected.

Farage's return to frontline British politics last year has reshaped the country's political landscape, with Reform UK climbing in national opinion polls while drawing support away from the Conservatives and increasing pressure on Britain's major parties.