Sir Keir Starmer has denied lockdown rules were broken when he had voice coaching lessons during the Covid-19 lockdown.

Leonie Miller was invited to coach the then-opposition leader on his response to Boris Johnson's Brexit deal, leading to accusations of a potential rule breach.

Ms Miller qualified for keyworker status and also wore a face mask during her visit to Labour headquarters on Christmas Eve in 2020, according to a book about the party's rise to power.

When questioned as he left a Nato press conference in Brussels, the prime minister told reporters "of course" he had not breached restrictions in place during the coronavirus pandemic.

Johnson announced his Brexit deal with the EU on 24 December 2020, the same week as he put London and the south-east into Tier 4 lockdown, forbidding households to mix indoors and effectively cancelling Christmas celebrations for many.

A "jingle and mingle" Christmas party had been held at Conservative HQ and at least three drinks gatherings took place in Downing Street during those lockdown restrictions.

Details about the voice coach's visit were revealed in excerpts of Get In, a book on Sir Keir's leadership being serialised by the Sunday Times.

Tory former minister Richard Holden wrote to the prime minister to ask whether he thought it had breached the restrictions, insisting he had "serious questions" to answer.

Reporters, who had travelled to Belgium but were not among the three journalists selected to ask a question, shouted questions asking whether he had broken the rules as the PM left the podium.

"Of course not," he replied, as he walked away.

Back in London, the prime minister's official spokesman had repeatedly refused to be drawn on the claims and, asked if Sir Keir considered the voice coach to be a key worker, said: "I'm not going to get into any matter to do with the opposition.

"The Prime Minister is focused on delivering on the Government's priorities and the people's priorities."

Asked if he still used a voice coach, the spokesman said: "Not that I'm aware of."

In an interview with Times Radio, the minister for school standards, Catherine McKinnell, said the incident contrasted "quite sharply" with the lockdown parties being held in Downing Street and in Conservative HQ at the time.

"As far as I'm aware there were no Covid rules broken," she told Times Radio.

"People were able to go to work and undertake really important roles and that was clearly a very important moment in Britain where an important public statement had to be made."

Sir Keir and deputy PM Angela Rayner were cleared of an alleged lockdown breach in April 2021.