Reform has denied all claims by Mr Everett, a former member of Mr Farage’s campaign team in Clacton, saying that he is “a disgruntled former councillor”.

His claims included that Reform did not report around £9,000 of spending on leaflets, banners, rosettes and the refurbishment of an office bar, which would have taken Mr Farage over the £20,660 spending limit in Clacton last year.

Mr Everett has given documents, including the spending return and photographs of items he said were not reported, to Essex Police. The force is expected to decide whether to formally investigate the matter in the coming days.

Mr Farage has not spoken publicly about the claims since The Telegraph first reported them on Sunday evening. He is understood to have returned from a weekend at the Formula One race in Abu Dhabi.

Ms Turley told The Telegraph: “These allegations are incredibly serious. Nigel Farage is treating the British people with contempt by staying silent – he needs to urgently come out of hiding on this issue. His constituents and the wider public deserve to be reassured that neither he nor his party have broken the law.

“Whether it be racism allegations, his refusal to investigate pro-Russian links, or now serious questions over whether his own election campaign broke the rules, Nigel Farage has proven that he can’t shake these issues off with bluster alone.

“He prides himself on being straight talking, yet he can’t find the words to shut these issues down.”

An Electoral Commission spokesman said: “We are not investigating Reform UK’s spending at the general election. The commission regulates the political finance laws which apply to parties and campaigners. It does not regulate candidate spending and donations, which is a matter for the police.”