British holidaymakers could visit destinations including Italy and France this summer if Covid-19 cases there can be driven down to UK levels, a senior scientific adviser has said.

Professor Neil Ferguson, from Imperial College London, whose modelling work informs Government scientists, said he had not yet booked a break abroad but the risks were focused on countries with higher infection levels than the UK.

It comes after the European Commission said it would ease restrictions on travel to the bloc amid progressing Covid-19 vaccination campaigns and lower infection rates.

The EU is proposing “to allow entry to the EU for non-essential reasons not only for all persons coming from countries with a good epidemiological situation, but also all people who have received the last recommended dose of an EU-authorised vaccine”.

The UK Government’s “green list” of countries to which people can travel without having to isolate for 14 days on their return is also expected to be released shortly.

Prof Ferguson told BBC Radio 4’s Today programme: “I think if for instance, by the summer, infection levels in France and Italy are the same sort of level as they are here, then there’s no risk associated with travelling overseas.

“The risk comes from going from a place like the UK with very low infection levels and going to a place with much higher infection levels and therefore having the risk of bringing infection back.

“If the two places are at comparable levels, and that’s what the EU is saying, then there is no particular risks associated with travel.”

He said the risk of vaccines being less effective in the face of variants was “the major concern” that could still lead to a “very major third wave in the autumn” in the UK.

We do expect transmission and, to some extent hospitalisations and deaths, to tick up in late summer if we completely go back to normal, but at a much lower level than we saw, for instance, back in December and January

It was therefore “essential we roll out booster doses, which can protect against that, as soon as we’ve basically finished vaccinating the adult population, which should finish by the summer,” he said.

Prof Ferguson said he was “feeling fairly optimistic that we will be not completely back to normal, but something which feels a lot more normal by the summer”.

Agreeing that “everybody would like to safely reopen international travel”, he added: “The EU in their statement did have a very strong caveat that they reserve the right to clamp down again if there were variants of concern, and I think that’s everybody’s concern at the moment across the European continent, that we don’t want to see vaccination undermined by things like the South African variant spreading in an uncontrolled manner, but with that one caveat, if we can find ways of reopening international travel which mitigates that risk, then I think everybody would like to be able to have some opportunity to go overseas.”

Commenting on the Prime Minister’s view that the one-metre plus rule on social distancing could be scrapped in June, Prof Ferguson said it was a political judgment on how much infection was acceptable, given deaths had been driven down.

He said “we do expect transmission and, to some extent hospitalisations and deaths, to tick up in late summer if we completely go back to normal, but at a much lower level than we saw, for instance, back in December and January”.

“So it’s obviously a political judgment as to what is acceptable in terms of number of infections, but we don’t see any prospect of, for instance, the NHS being overwhelmed – with the one caveat around variants I’ve already mentioned – so it’s always a matter of judgment.”

He said there would need to be “much higher levels of infection in society in order to risk overwhelming the NHS and we think that’s actually unlikely to happen unless a variant comes along which resets that relationship again.”

Prof Ferguson stressed that his team still do have some concerns about late summer and early autumn but “they’re diminishing”, particularly in light of new data showing the effect of vaccines on transmission of the virus.

“And so that has pushed our estimates of the scale of any potential autumn wave down,” he said.

Meanwhile, Portugal’s secretary of state for tourism, Rita Marques, said the country is “taking the lead” at the European Council in negotiations aimed at opening up the European Union to UK holidaymakers.

She told BBC Breakfast: “We are really pushing hard to open up to third countries like the UK.”

But International Trade Secretary Liz Truss urged people to wait for an announcement from the UK’s travel taskforce, telling Sky News: “I would encourage people to wait until we make that announcement so that we can see exactly what the details are, based on the data, because what we don’t want to be doing is reimporting this virus after we’ve done such an excellent job in getting the levels down in the UK… we need to be cautious and we need to make sure that we’re not simply importing the virus after we’ve successfully dealt with it in Britain.”

Elsewhere, Professor Stephen Reicher, from the University of St Andrews and a member of the sub-committee on behavioural science which advises the Scientific Advisory Group for Emergencies (Sage), said the public should take the Prime Minister’s announcement that social distancing could be scrapped in June with a “little bit of a pinch of salt”.

He told BBC Breakfast that “things can change very rapidly”, adding: “I think the critical issue for us now is how do we bring infections down so the data does look good, and we can relax things in two months’ time, and the real important issue is this – if we take this as a signal that things are all over, if we relax and if we mix now, the paradox is we will push up the infections and will make it less likely that we can relax on June 21.”

Prof Reicher said people will need to be careful in future, but not in a way that limits daily life.

“Even after restrictions go, it makes sense to have sensible and cautious precautions; not in a way that limit our everyday lives, not in a way that stops us seeing people or hugging people, but just realising, for instance, that on the whole, we are safer outside, don’t sit too close to people, open the windows,” he said.

“So we need to be sensible about this, we need to be cautious about this, and in that way I think we’re much more likely to get to a space where our lives are much more back to normal, much more tolerable, where we can meet and hug our loved ones, but don’t just hug anybody.”

Asked about the use of face masks in the future, Prof Reicher said “the whole point is we’re going to move away from prescriptions” but said people could still be sensible, such as opening windows and not sitting too close to other people.