Boris Johnson and health experts have urged people to exercise caution when they head to pubs and restaurants as the lockdown eases despite concerns about the spread of an Indian coronavirus variant.

Although ministers believe the vaccines will be effective against the highly transmissible Indian variant of concern, there are worries about the impact of its spread on those who have refused to have a jab or not yet been offered one.

The Prime Minister urged people to treat the latest easing of restrictions with a “heavy dose of caution” while Business Secretary Kwasi Kwarteng warned against excessive drinking for those returning to bars.

From today:

– People in England can meet outdoors in groups of up to 30, and indoors in groups of six, or two households, with pubs and restaurants able to serve customers inside.

– Museums, cinemas and other indoor attractions can reopen.

– The “stay in the UK” restriction will lift and people will be able to go on holiday to “green list” countries including Portugal without having to quarantine on their return, provided they take one post-arrival test.

– Wales moves to alert level two with the reopening of indoor hospitality and entertainment venues.

– In most of Scotland, six people from three households will be able to meet indoors, the same number can meet in a hospitality venue, and eight people from eight houses can meet outdoors.

– But Glasgow and Moray will remain under Level 3 of the five-tier system, meaning pubs cannot serve alcohol indoors.

The threat posed by the Indian variant led the Prime Minister to warn that the final stage of England’s road map out of lockdown could be delayed from the June 21 target.

“We are keeping the spread of the variant first identified in India under close observation and taking swift action where infection rates are rising,” Mr Johnson said.

Scotland’s First Minister Nicola Sturgeon said people should be cautious and “very careful”.

Sir Jeremy Farrar, director of the Wellcome Trust told BBC Radio 4’s Today programme: “I think it is reasonable to just be sensible about knowing where transmission is occurring, mostly indoors, mostly in larger gatherings indoors with lots of different people, different families, different communities, and I would just restrict that at the moment personally.”

But he added: “I don’t think it’s unreasonable to lift the restrictions – we do need to lift the restrictions at some point, we’ve been in restrictions now for a very long time.”

Mr Kwarteng insisted the June 21 date for the ending of restrictions in England was still likely to be met.

He told Sky News that “people should have common sense, they should use judgment and I think if we act in a reasonable way, there is no reason to suppose that we can’t reopen the economy entirely on June 21”.

On LBC Radio Mr Kwarteng he said: “We need to be cautious because if we get too carried away and the mutant variant spreads too quickly, that could endanger our ability to open up on June 21.”

Professor Graham Medley, a member of the Government’s Sage scientific advisory panel, told LBC the chances of the June 21 date being delayed was “well less than 50%” but added “it is uncertain”.

The main cause for concern is the Indian variant, which is on the way to becoming the dominant strain in some places including Bolton and Blackburn.

A major campaign has been launched to encourage people in those areas to receive a jab.

Mr Kwarteng said he did not want to “stigmatise people” over vaccine hesitancy, but told BBC Radio 4’s Today: “We’re not exactly where we want to be among certain communities but I think the take-up has been much greater in the last few months and more and more people are convinced that this is the way to keep themselves and their families safe.”

Dr Helen Wall, who is leading the vaccination effort in Bolton, said that over the weekend more than 6,200 vaccines were administered in the area.

She told BBC Breakfast that before the weekend there were around 10,000 people in the area in the highest priority groups, those deemed to be clinically vulnerable and the over-50s, who were yet to be vaccinated, but added: “I’m hoping that we’ve made a big dent into that now”.

Chris Hopson, chief executive of NHS Providers, said there were “concerns” about small numbers of older people who are yet to take up their vaccine offer.

“The biggest risk comes from, if there are large numbers of older people who are unvaccinated,” he told Times Radio.

Health Secretary Matt Hancock will update MPs on the situation in the Commons on Monday afternoon.

Mr Kwarteng defended the timing of tougher restrictions being imposed on travel from India amid speculation decisions may have been delayed due to the Prime Minister’s planned trade mission to the country in April.

India was placed on the red list, effectively banning travel except for returning Britons who had to go into a quarantine hotel, on April 23.

“It is easy with hindsight to say things could have been better or quicker and all the rest of it, but I think there was a balanced approach,” he said.

Despite the pleas for caution, some drinkers took advantage of the relaxations to sink pints shortly after midnight.

One of those inside the Showtime Bar in Huddersfield, West Yorkshire was Finlay Woodhead, 20, who could barely contain his excitement at being back in a pub.

“I’m over the moon, I’ve been waiting so long,” he said.

“It’s so nice to be sat inside where it’s warm.

“I love it, honestly, I love it.”