THE Prime Minister has been accused of breaching ministerial rules during a televised coronavirus press conference this week.

During the Monday briefing, Boris Johnson accused London mayor Sadiq Khan of “blowing” Transport for London finances with an “irresponsible fares policy”.

Downing Street is currently in a pre-election purdah period, which means there are limits on government publicity before the London mayoral election on May 6.

Labour’s deputy leader Angela Rayner has now written to Simon Case, head of the Home Civil Service, accusing the Tory leader of breaking the rules in a “political attack” on Khan.

The National:

In her letter, Rayner (above) said the ministerial code is clear that “official facilities and resources may not be used for the dissemination of party political material”.

She argued the comments, made in Number 10’s new multi-million-pound media conference room, were “entirely unrelated” to the questions put to the Prime Minister.

Rayner called for an investigation into the comments and called on Johnson to publicly apologise “for misusing public resources for party political gain and misleading the public”.

Khan has rejected Johnson’s claims about finances at Transport for London, accusing Johnson of using Monday’s conference to spread “lies”.

READ MORE: Scottish election: Holyrood set for large pro-independence majority, poll shows

He insisted that when he first became mayor the TFL deficit was more than £1.5 billion – and that he reduced it by more than 71% before the coronavirus pandemic.

The mayor said during Johnson’s time in the role, he “increased TfL’s debt by more than £7bn”.

He commented: “I think it is inappropriate for all of us to follow the rules and abide by the rules, and Boris Johnson to yet again break the rules in the way he’s done.

“Firstly, during the purdah period using a government platform to attack a Labour candidate. But secondly, to tell lies.”

READ MORE: Boris Johnson may not campaign in Scotland before election, Douglas Ross admits

Meanwhile, Scottish Tory leader Douglas Ross admitted Johnson may not travel to Scotland to campaign ahead of the upcoming Holyrood election.

Johnson previously insisted he could not be kept away from the campaign – despite his abysmal approval ratings in Scotland.

Ross said he had “previously expected” Johnson to travel north before May 6 but was now not sure, saying the coronavirus pandemic had resulted in a “very different” kind of campaign.

This is despite Johnson prompting fury by travelling to Scotland in January, weeks into the nationwide “stay at home” order when coronavirus infection levels were significantly higher.