Britain’s Prime Minister has set out a three-tier system of lockdown measures for England to prevent an “intolerable” COVID-19 death toll.

But Boris Johnson’s new ‘traffic light’ system of curbs has been slammed by local ministers for not going hard enough on coronavirus hotspots.

He has proposed for regions to be placed under “medium”, “high” or “very high” alerts, depending on their local infection rates.

It is seen as an attempt to standardise a patchwork of often complicated and confusing restrictions imposed across England.

If MPs vote to approve the measures on Tuesday, pubs and bars that don’t serve “substantial meals” will have to close in areas under a “very high” alert level.

So far, the Liverpool city region is the only part of the country to be placed into a “very high” COVID-alert category.

Britain has already imposed partial lockdown restrictions on Liverpool that meant different households could meet only in outdoor public spaces and hospitality for food and drink has been restricted to table service. So far, there has been no travel ban.

Revellers in Liverpool pictured partying up until the 10pm curfew on Saturday. Photo: AAP

Mr Johnson said gyms, leisure centres, casinos, betting shops and adult gaming centres in the city would also close.

The British government website explains that people living in “high” risk category areas such as Manchester or Leeds must not meet with anybody outside their household or support bubble.

They also won’t be allowed to meet in groups of more than six outside and have been advised to walk or cycle where possible.

The only real restriction for those in “medium” COVID-alert categories is that they don’t meet in groups larger than six, indoors or outdoors.

Schools, universities and places of worship can remain open, weddings and funerals can go ahead, all businesses and venues can continue to operate –  but must close from 10pm-5am – and indoor sport and exercise classes can take place.

Welsh ministers have urged Mr Johnson to impose strict travel bans for areas with high rates of coronavirus infections.

The BBC quoted the Welsh government as saying First Minister Mark Drakeford had “expressed deep disappointment at the inadequate proposals for travel restrictions in high infection areas in England”.

Meanwhile, Mr Johnson told parliament “we must act to save lives”.

He said he did not want another Britain-wide lockdown and that he understood the frustrations of those chafing at the “repressions of liberty”.

“If we let the virus rip, then the bleak mathematics dictate that we would suffer not only an intolerable death toll from COVID, but we would put such a huge strain on our NHS (National Health Service) with an uncontrolled second spike that our doctors and nurses would simply be unable to devote themselves to other treatments,” he said.

Prime Minister Boris Johnson leaves 10 Downing Street on Monday. Photo: AAP

Health officials say the latest data showed infections are rising across the north of England and in some more southerly areas. The virus is creeping up age bands towards the elderly from those aged 16-29 years.

Manchester intensive care consultant Jane Eddleston said 30 per cent of critical care beds were taken up with COVID-19 patients, which was starting to affect healthcare for others.

“This is not how we want to live our lives but this is the narrow path we have to tread between the social and economic trauma of a full lockdown and massive human and indeed economic cost of an uncontained epidemic,” Mr Johnson said.

“The weeks and months ahead will continue to be difficult and will test the mettle of this country.”

But as millions of people across Britain grapple with restrictions, the hospitality sector said it was being brought to its knees by the government.

Karen Strickland, landlady of The Grapes pub in Liverpool, said her income was already down 70 per cent under the current enforced countrywide closing time of 10pm, and the government’s support scheme help was not enough.

“It’s absolutely horrendous,” she said, adding it made no sense to single out pubs.

Under the new restrictions, however, pubs that serve main lunchtime or evening meals will be allowed to stay open. They will be allowed to serve alcohol only as part of such a meal.

-with AAP