Reform UK confronts major financial scrutiny following revelations that a substantial undisclosed gift to party leader Nigel Farage triggered banking alerts for potential money-laundering risks. The £5m donation, reportedly from billionaire Christopher Harborne, was flagged to authorities months after its transfer, coinciding with timing that raises questions about when Farage committed to parliamentary candidacy. The controversy prompted Farage to announce his resignation as an MP and trigger a byelection in his Clacton constituency. Banking industry disclosures to the National Crime Agency also extended to other senior party figures, with over £1m in transactions prompting similar regulatory notifications.

The crisis has intensified scrutiny over the party's financial transparency and disclosure practices. Investigators are examining whether donations met parliamentary reporting requirements, particularly given uncertainties about when funds were fully transferred and whether Farage's stated rationale of receiving a "personal gift" outside his political involvement holds scrutiny. Questions remain unresolved regarding the source and purpose of a separate £1m donation funnelled through an associated organisation, with tracing efforts proving unsuccessful. The disclosures have prompted even Reform supporters to question the party's financial governance and leadership judgment.