BORIS Johnson has been served a county court judgement over an unpaid debt, it has been revealed.

A search of the county court judgments database shows the "unsatisfied record" registered to the Prime Minister at "10 Downing Street".

Failure to pay the £535 debt could result in enforcement action from bailiffs.

The date of the judgment, which was first revealed by the Private Eye magazine, is October 26 last year.

The official court records do not state who the creditor is, nor the nature of the debt.

The judgment was issued less than a fortnight after a Conservative donor told the party he was donating £58,000 to the party in relation to refurbishments at Johnson's Downing Street flat.

The Prime Minister has faced numerous questions about his finances as the Electoral Commission investigates whether any donation was properly declared.

Johnson has denied any wrongdoing and insisted he personally paid for the lavish refurbishments, but has declined to say whether he received an initial loan.

Scrutiny intensified when former aide Dominic Cummings accused the Tory leader of wanting donors to "secretly pay" for the renovations to the apartment in a "possibly illegal" move.

Tory peer Lord Brownlow said in an email leaked to the Daily Mail and dated October 14 that he was making a £58,000 donation to the Conservatives "to cover the payments the party has already made on behalf of the soon-to-be-formed 'Downing Street Trust'".

Downing Street appeared to be unaware of details of the county court judgment against Johnson although officials insisted it was not linked to the controversial refurbishment of the No 11 flat.

"I have seen that report, we are looking into this issue," the Prime Minister's official spokesman said.

"I can confirm it is nothing to do with the refurbishment of the Downing Street estate, where all such bills have been duly paid either by the Government or the Prime Minister personally."

Asked whether the Prime Minister could be trusted with the nation's finances if he could not manage his own, the spokesman said: "I think our record on the economy is very clear."