Nigel Farage is under renewed scrutiny regarding a £5 million donation from cryptocurrency tycoon Christopher Harborne, with new details emerging about the timing of the gift and Farage's discussions about a political return. The donation, made on April 5, was not disclosed by Farage, who stated it was a personal gift unrelated to political activities.

However, notes indicate that Farage had discussed standing in Clacton for the 2024 general election months prior to receiving the funds. He told reporters on June 3, less than two months after the payment, that Tony Mack, whom he replaced as the Reform candidate for Clacton, had been aware for "many months" that Farage's potential candidacy was a possibility. A Reform spokesman later confirmed to the BBC that Mack had been informed about six months earlier.

This situation unfolds as the by-election campaign in Clacton, triggered by Farage's resignation, officially commences. The contest has been described as potentially "farcical," with major rival parties declining to participate. Farage's main opponent is the satirical candidate Count Binface.

In January 2024, a poll commissioned by Reform candidate Arron Banks suggested Farage could win the Clacton seat if he stood in the general election. Following this poll, Farage reportedly told the Sunday Times it made him "consider getting back on the pitch far more seriously than ever before."

Mack, who was initially Reform's candidate for Clacton, stated on social media in June 2024 that Farage's decision to stand was a surprise. He later ran as an independent candidate, securing 317 votes. Mack has also indicated that he was told in January, after the poll, that he would be reimbursed for campaign expenses if Farage were to stand, suggesting prior planning by the party.

Farage is currently being investigated by the Parliamentary Commissioner for Standards concerning the £5 million received from Harborne. Farage initially suggested the funds were for his personal security but later described it as both a "reward" for his Brexit campaigning and an "unconditional gift."

Further questions have been raised about undeclared donations from George Cottrell, a Reform supporter known as 'Posh George,' who has been convicted of fraud. Cottrell reportedly recruited and paid staff for Farage's social media efforts before the general election and has allowed Farage to use a London property he rents.

New MPs are generally required to register gifts exceeding £300 received in the preceding 12 months if they could reasonably be seen to relate to political activities. Farage has argued that calling the by-election was necessary to break a "paralysis" within Reform UK caused by ongoing questions about his personal finances and interests, stating that a "daily media pile-on" necessitated decisive action. He also criticized the House of Commons sleaze investigators, calling them a "kangaroo court" and alleging bias among some committee members.