Keeping borders open for international travel could risk undoing vaccine progress, a scientist has warned.

Dr Mike Tildesley, a member of the Scientific Pandemic Influenza Group on Modelling (Spi-M), which advises the Government, has said allowing overseas trips without efficient testing and tracing in place could enable a vaccine-evading variant to enter the UK.

Under current guidelines, while it is illegal to travel abroad for holidays, travel for a range of professions including defence personnel and some HGV drivers is permitted.

Travellers returning from countries included on the ‘red list’ where coronavirus cases are higher must quarantine in a Government-approved hotel for 10 days.

Ministers are facing pressure to protect the success of the vaccination programme against the import of new variants from overseas, with the Guardian reporting officials met on Friday to consider expanding the red list.

Dr Tildesley, an infectious diseases expert, told Times Radio: “I can understand the need for wanting to keep our borders open for as long as possible, but if we are, there’s a risk there.

“We need to do what we can to minimise the risk, because what we don’t want is new variants coming in that undo all the good that our vaccination programme has done.”

He added: “If we are going to allow travel to continue we clearly need to do something about making sure that testing is much more efficient at airports and making sure that tracing works, and also that people are isolating for the full period, and we need to give people the support to do so.”

Earlier this week, the Prime Minister said the “natural wanderlust” of Britons will lead to a “miraculous change” in the desire to holiday abroad, implying that summer holidays could still be on the cards – though he acknowledged things are “looking difficult” in Europe where transmissions are rising.

Under the current ‘road map’ for easing restrictions, the earliest date people in England could go on holiday abroad would be May 17, and Boris Johnson has said details of a review being carried out by the international travel taskforce will be revealed on April 5.