LONDON — The British billionaire James Dyson denied acting inappropriately for seeking tax assurances from prime minister Boris Johnson to work on a project to manufacture ventilators in the early days of the coronavirus pandemic.

In his first public comments since Mr Johnson faced scrutiny over the interaction with the opposition Labour Party calling for an investigation into lobbying, Mr Dyson said it was untrue he tried to "extract favours from the prime minister".

The BBC reported that Mr Dyson had asked the finance ministry for no change in the tax status of his staff coming to Britain to work on the emergency project. He contacted Johnson directly, who replied: "I will fix it", the BBC said.

Mr Dyson, inventor of the bagless vacuum cleaner, rejected what he called the BBC's "grotesque mischaracterisation" of his connections to Mr Johnson's Conservative Party.

"The BBC’s characterisation of me as a prominent Conservative donor, or supporter, leveraging a position of power to extract favours from the prime minister, is completely untrue," Dyson said in an article in the Daily Telegraph.

"I have met Boris Johnson only three times — always with officials — the last time in 2016. I have not attended any Conservative social events."

The BBC defended the organisation's reporting.

"The BBC has led the way on reporting a significant story which is clearly in the public interest," a spokesman said.

"James Dyson has informed us he is not a prominent Conservative supporter and at his request we put that detail on the record."

Mr Johnson is currently grappling with an array of accusations which opponents say show he is unfit for office, including claims he lied about who paid for the refurbishment of his official Downing Street flat. REUTERS