Nigel Farage has suggested he expects Parliament’s standards commissioner to find against him over a £5 million gift, while defending the money as necessary to fund his personal security.

The Reform UK leader is being investigated over whether he should have declared the gift from cryptocurrency billionaire Christopher Harborne. Commissioner Daniel Greenberg interviewed him for around 30 minutes in September.

Asked whether he expected an adverse finding, Farage replied: “Do I think the establishment would find against me, the leader of an insurgent party? What a question to ask.”

His answer framed the investigation as a confrontation with the establishment. The question under Commons rules is narrower: whether the gift required registration.

New MPs must register gifts worth more than £300 received during the preceding 12 months, unless they “could not be reasonably thought by others” to relate to their political activities. Farage’s argument that he needs money for security explains his defence of accepting the gift; whether it falls within that exemption remains unresolved.

Farage also criticised restrictions on discussing the investigation. He said: “Under the rules of Parliament, if I even answer your question, I will receive a letter of rebuke from the standards commissioner.” He nevertheless confirmed that he had been interviewed.

Separately, Harborne and fellow cryptocurrency billionaire Ben Delo have each donated £36 million to Reform, a combined £72 million. Those party donations are distinct from the £5 million personal gift under investigation.

The donations have renewed calls for a blanket cap, going beyond legislation aimed at restricting money from overseas sources. Harborne is based in Thailand, but was reported in June to have registered to vote in Hampshire. The wider debate concerns limits on political funding; the commissioner’s investigation concerns Farage’s disclosure obligations.