Professor Chris Whitty told MPs the situation could “turn bad” very quickly if the easing of lockdown restrictions are rushed and a close eye is not kept on it.
Appearing at the Science and Technology Committee he said: "I think a lot of people may think that this is all over.
"I would encourage them to look at what is happening in continental Europe at the moment where a lot of countries are going back into rates going up and having to close things down again having not been in that situation before. I think it's very easy to forget quite how quickly things can turn bad if you don't keep a very very close eye on it."
It came as Nicola Sturgeon announced some rules on outdoor meeting in Scotland will ease from Friday,with four adults from two households able to meet outside from then.
The number of daily Covid deaths and cases in the UK dropped to the lowest levels in five months on Monday.
