Police investigating breaches of lockdown restrictions at Downing Street have said they will not be providing any more updates on new fixed-penalty notices until after next month’s local elections.

The investigation is continuing after Boris Johnson this month became the first serving prime minister to be found to have committed a criminal act while in office when he was fined over breaching his own Covid rules.

However, Scotland Yard’s announcement that it would not be releasing any more updates until after the 5 May elections potentially spares Johnson further ignominy, were it to be made known that he had received further fines.

A Metropolitan police spokesperson said: “Whilst the investigation will continue during the pre-election period, due to the restrictions around communicating before the May local elections, we will not provide further updates until after 5 May.”

Johnson is facing another three potential fines for lockdown breaches, according to senior sources.

While the Met’s statement indicates the force will not be pro-actively announcing any new fines, the media and others may still become aware of developments by other means.

Downing Street appeared to indicate that it will still say whether Johnson or the cabinet secretary, Simon Case, are fined before the local elections, although it stopped short of committing to explicitly revealing any fines as soon as they were issued.

A No 10 spokesman told the Press Association: “We’ve committed before to being transparent and to letting people know if [penalty notices are issued]. That hasn’t changed. But specifically the announcement made today – it’s clearly a matter for the Met police, it’s their investigation and it’s an independent matter for them.”

Asked if No 10 making such a disclosure would render the police’s silence on the matter irrelevant, the spokesman said: “We’ve said, given the public interest, that we would make people aware if the prime minister or if the cabinet secretary received a fine.”

The Met said on 12 April that its investigation into allegations of lockdown-breaking parties held by politicians and staff at the centre of government had led to more than 50 fixed-penalty notices. As well as Johnson, those issued with notices have included the chancellor, Rishi Sunak, and the prime minister’s wife, Carrie.

The prime minister spoke on Tuesday of his “humility” as he addressed MPs for the first time since receiving his fixed-penalty notice for breaching lockdown rules in June 2020.

The notices issued to him, Carrie and Sunak were all for attending a birthday gathering for the prime minister in No 10.

Other events the Met is expected to examine, which Johnson attended, include a May 2020 summer party, a November gathering in Johnson’s flat with his wife on the day of the departure of his senior adviser, Dominic Cummings, and a leaving do for Lee Cain, a senior aide, in No 10 a day later.

While MPs have rallied to Johnson’s defence on social media and in parliament, there have been warnings from within his own ranks that fines could still prove “fatal” for the prime minister’s career.

Those Tory MPs seeking to oust Johnson had been considering the aftermath of dire local election results as their next chance to press for his removal.

The extent to which Partygate is likely to impact on the local elections remains to be seen but a snap YouGov poll this month found that three-quarters of people thought Johnson knowingly lied when recounting the events concerned, and 57% felt he should resign.