The government must tell British people they need to stay at home and end its "mixed messages", Manchester Mayor Andy Burnham has said.
Mr Burnham said Downing Street needed to make its message much simpler to stop people taking to the streets.
It came after a weekend which saw people flood to outdoor areas and gather in groups - despite clear advice that doing exactly that would spread the coronavirus and cause more preventable deaths.
Speaking on Good Morning Britain, Mr Burnham the PM's messages are "clearly not working".
He added: "Just look at the scenes around the country at the weekend.
"And look I don't blame the public, I think the messaging is mixed.
"We had the Prime Minister in Downing Street saying it was okay to get out and about - speaking next to a podium that said 'Stay At Home.
"He was then saying stay two metres apart in a packed room in 10 Downing Street.
"So the messages are completely mixed.
"We need to move today to a 'stay at home' policy, that was the message coming from NHS staff at the weekend."
This morning Ministers said they are examining the curfews and restrictions imposed in Europe as a method of controlling the spread of coronavirus.
He said the "unpleasant and very difficult times" meant that it was possible the authorities, including the police, could be required to order people to follow the rules on social distancing.
And he said that "nothing is off the table" if further curbs on people's freedoms were required to slow the progress of Covid-19 through the UK.
Prime Minister Boris Johnson appeared shocked at the prospect of the police being brought in to enforce coronavirus restrictions when asked about it at a press conference on Sunday.
But Mr Hancock said officers had already been given the powers to force the closure of bars and restaurants and indicated that other restrictions would be considered.
The Health Secretary condemned the "very selfish" behaviour of people who were ignoring social-distancing rules.
Asked whether tighter controls would be imposed, he told BBC Radio 4's Today: "We are, of course, monitoring how much people are following those rules."
And he added: "We will act if we need to.
"As Health Secretary it is my job to protect life and the way that we protect life from a virus like this is to stop its spread and the way that you stop its spread is by people not interacting with others."
Measures imposed across Europe have included curfews or preventing groups of more than two people gathering in public.
"Nothing is off the table," Mr Hancock said.
"Of course we are looking at what other European countries are doing.
"There are a series of different measures that other countries have taken, now they are further down the curve - they have higher numbers of cases than we do here - but that means that we can act sooner and earlier in this epidemic.
