Scotland Yard has announced it will not issue any more Partygate updates before the May 5 elections.
The Metropolitan Police said it would continue to investigate Covid law breaches during the campaign period.
But senior officers are believed to be concerned that providing any more updates on their probe could sway voters.
Scotland Yard has already issued 50 fines as a result of their investigation into Covid law-breaking at the heart of the Government during the pandemic.
It was reported the Met could continue to issue fines, but not make a public announcement about doing so until after May 5. This would present a dilemma to Boris Johnson, who could receive up to five further penalties.
A Met Police spokesman 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.”
Ministers are advised not to announce long-term initiatives or use public money "for party political purposes" in the three weeks before polls open.
But the specific restrictions on communications, known as purdah, do not usually apply to the police in the run-up to local elections.
Boris Johnson was accused of breaking the rules on the first day of purdah last week when he announced his Rwanda asylum plan.
It came as it emerged Tory MPs would get a free vote on whether to investigate claims Boris Johnson lied to Parliament over the affair.
After a government U-turn, there will just be a vote this afternoon on whether to refer Boris Johnson to the Privileges Committee over four alleged misleading statements.
And instead of being whipped to defend their boss, Tory MPs will get a free vote - dramatically raising the chances of an investigation being triggered.
Labour’s leader said the principle of telling the truth was “under attack”, telling Parliament: “The Prime Minister has been accused of repeatedly, deliberately and routinely misleading this House over parties held in Downing Street during lockdown.
“Now that’s a serious allegation because if it’s true, it amounts to contempt of Parliament. And it’s not, and it should never be, an accusation that is made lightly.”
“This is about honesty, integrity and telling the truth in this case,” Labour’s leader added. He went on: “It is a British principle - it’s a principle that’s been cherished by Conservatives for as long as their party has existed.”
In a devastating speech, Tory MP William Wragg - who has called for Boris Johnson to quit - condemned the "toxic" atmosphere under his leadership.
He said: “The invasion of a sovereign nation by a dictatorial aggressor should not be a reason why we should accept lower standards ourselves”.
Mr Wragg said "it is utterly depressing, defending the indefensible", before adding "each time, a part of us withers".
And senior Tory MP Steve Baker called for Boris Johnson to quit for not obeying the Covid rules he set. Mr Baker, a committed Christian and renowned rebel Tory, said the chance to forgive the Prime Minister "had really long gone".
The Commons chamber became eerily silent as Mr Baker had spent much of the debate, urging colleagues to exercise forgiveness whilst quoting scriptures from the Bible.
But he suddenly turned and said: "I've been tempted to forgive.
"But I have to say now the possibility of that really has gone. I'm sorry but for not obeying the letter and the spirit, the prime minister must be long gone... The Prime Minister should know the gig's up".
