Boris Johnson has delivered an ultimatum to Dominic Cummings over his lockdown trip to Durham, according to reports.
The Prime Minister warned his chief aide he is on his "last chance" and that he "will not tolerate" another mistake, the Mail on Sunday reports.
Mr Cummings - who sparked huge public backlash after making a 264-mile trip to Durham with his wife and son while ill with coronavirus symptoms in March - has reportedly been firmly told to stay out of the public eye.
No10 sources say the top aide will no longer be allowed to make media appearances or write blog posts.
One told the paper: "The Prime Minister has made it absolutely clear that Dominic cannot be the story again.
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"He will not tolerate it. If it happens again, he’s out."
Another Downing Street official says the controversial aide has been "firmly put in his place".
"I don’t expect there will be any blog posts or media appearances by Dom for a very long time," they added.
Durham Police last week ruled that Mr Cummings may have breached lockdown rules when he drove to Barnard Castle on April 12, a 30-mile trip which he later said was to test his eyesight.
The PM has stood by his right-hand man, saying he has acted with "integrity" at all times.
However, it is understood Mr Johnson is angry with the way his aide sparked backlash after being questioned by journalists outside his house last Saturday.
Emerging from his house soon after the allegations surfaced, Mr Cummings berated reporters, saying: "Who cares about good looks? It’s a question of doing the right thing. It’s not about what you guys think."
This evening, a Change.org petition calling on Dominic Cummings to be sacked has received more than one million signatures.
It was set up by a user called Gary Kelly on May 25.
It states: "The PM's chief aide Dominic Cummings is facing calls to resign after it emerged he travelled from London to his parents' home in Durham with coronavirus symptoms during lockdown."
One of the top government scientific experts also made his view on the Dominic Cummings row clear at the Downing Street press conference this afternoon.
Professor Jonathan Van-Tam, deputy chief medical officer, was asked by the Observer's Toby Helm about the advisor's travel to Durham.
Prof Van-Tam replied: "In my opinion the rules are clear and they have always been clear.
"In my opinion they are for the benefit of all and they apply to all."
