Boris Johnson will urge the public not to overdo it when pubs and restaurants reopen in a warning that the health of the economy “is dependent on every single one of us acting responsibly”.

The Prime Minister will lead a Downing Street press conference ahead of the easing of the lockdown in England on Saturday, which will be a major test for keeping coronavirus transmission down.

He is expected to impel people to act safely or run the risk of the Government “putting on the brakes” and bringing back severe restrictions, as has been witnessed in Leicester.

The lockdown imposed on March 23 suppressed Covid-19’s spread by drastically reducing the people’s contacts, but the reopening of the economy will be a tense moment in the battle.

Speaking on Friday, Mr Johnson is expected to paint the easing in England as a means of supporting the livelihoods of bosses and their employees but warn “we are not out of the woods yet”.

“They are our local restaurants, hairdressers, libraries, museums, cinemas, and yes, pubs. They are also hotels, B&Bs, indeed much of our tourism industry,” he will say, according to an extract released to the media ahead of the speech.

“All these businesses and their workers have put in a heroic effort to prepare their venues for this reopening, to work out a way to trade in a way that keeps their customers safe.

“But the success of these businesses, the livelihoods of those who rely on them, and ultimately the economic health of the whole country is dependent on every single one of us acting responsibly. We must not let them down.

“The virus is still with us and the spike in Leicester has shown that. If it starts running out of control again the Government will not hesitate in putting on the brakes and re-imposing restrictions.

“Anyone who flouts social distancing and Covid-secure rules is not only putting us all at risk but letting down those businesses and workers who have done so much to prepare for this new normal.”

On Friday, the Prime Minister’s official spokesman said Mr Johnson will be warning people not to “overdo it”.

Asked if Mr Johnson would be visiting a pub or restaurant on Saturday, the spokesman said: “He’s talked about his enthusiasm for a haircut and pint previously but I don’t know exactly what he’s doing on Saturday yet.”

The spokesman added that it would be “plain for all to see next week what he’s been doing at the weekend” if he gets his blonde mop trimmed over the weekend.

It comes after the Treasury was forced to delete a tweet from its official account on Wednesday evening urging people to “grab a drink and raise a glass, pubs are reopening their doors from 4 July”.

The department was accused of sending “the most tone-deaf tweet in history” by journalist Piers Morgan, who said: “65k people dead, the economy catering, millions facing unemployment … and the Treasury wants us all to go out on the piss & celebrate.”

A Treasury source said: “We got it wrong on this and the tweet was quickly removed.”