BORIS Johnson today vowed to take "very, very draconian action" to stamp out alarming Covid mutations - but stressed the roadmap remains on track.
The PM tried to sooth fears on a visit to a vaccine centre in East London that June 21's freedom day is in peril over worries about the India variant.
Moving to assuage concerns he said: "At the moment we see nothing conclusive that we have to deviate from the roadmap".
And he suggested a crunch data meeting in a few days time would tell us all more, urging the nation to hold tight.
He warned the nation to be cautious and vowed: "We're keeping everything under very close observation - we'll know a lot more in a few days' time.
"We're looking very carefully at the data, we're looking at the epidemiology. We're trying to work out what extent the Indian variant may be more transmissible."
Under fire from critics for dithering to ban travel with India, he insisted the Government would come down hard to extinguish emerging strains.
The PM said: "We will continue to take very, very draconian action in respect of all variants coming from wherever around the world."
Hailing Brits' willingness to get the vaccine, he thanked everyone who had been jabbed so far.
The PM said: "A poll out last night showed that of all the countries in the world we are the most positive about vaccinations.
"The numbers are incredibly high. I know that some people have been more vaccine hesitant than others but actually across the whole of society the numbers continue to go up, in every age group.
"And that's very very encouraging and I would urge everybody who is eligible get a vaccine, when you get your call up, come and get your jab."
He also moved to clear up confusion over holidaying to amber list countries after one of his senior ministers suggested people are allowed to trave.
The PM said: "I think it's very important for people to grasp an amber list country is not somewhere where you should be going on holiday.
"Let me be very clear about that and if people do go to an amber list country, that they absolutely have to for some pressing family or urgent business reasons they have to go to amber list country then please bear in mind that you will have to self-isolate, you'll have to take tests and do a passenger locator form, and all the rest of it, but you’ll also have to self-isolate for 10 days, when you get back."
Last night Government advisers warned that some rules such as masks or social distancing are likely to stay after June, when the PM has previously said he hopes all rules will be able to be ripped up.
But fears over the new Indian variant of Covid, which is spreading much quicker in some communities, is causing ministers to urge extra caution.
The PM last week warned that June 21 could mean some planned rules may have to stay.
No10 has also refused to rule out local lockdowns or a return to the hated tiers system which split England up into several areas with different rules.
It comes as:
- A minister caused more confusion over holidays by saying travel to amber list countries to visit friends is OK - but holidays aren't
- Fears grew that pubs in Scotland may need to shut as the Indian variant spreads
- Under a proposed new tiers system, some pubs and shops may be shut again
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Officials have said they will give at least a week of notice ahead of June 21 before confirming whether the roadmap will be eased further as planned.
But the move leaves Brits in limbo who are trying to plan events after June 21, and the hospitality trade who want all rules to be ripped up so they can host more customers.