Nigel Farage, the leader of Reform UK and a member of Parliament, is facing a formal investigation by the parliamentary standards watchdog after failing to declare a 5 million-pound ($6.8 million) gift from crypto billionaire Christopher Harborne, news services including the Guardian reported Wednesday.

Farage received the donation from Harborne, a Thailand-based businessman with a 12% stake in stablecoin issuer Tether, weeks before announcing he would stand as a candidate in the 2024 general election, and did not declare it when elected as MP for Clapton. New MPs must register all financial interests received within the 12 months preceding their election.

A weekly YouGov poll of voting intentions has Reform UK gaining the largest share…