The Beta variant of coronavirus spreading in France poses a “threat” to the UK with evidence suggesting it may evade the effect of vaccines, a scientist involved in advising the Government has warned.

Professor John Edmunds, of the London School of Hygiene and Tropical Medicine and a member of the Scientific Advisory Group for Emergencies (Sage), said he could understand concerns over the variant that have led to last-minute travel rule changes.

It was announced on Friday evening that holidaymakers returning to England from France must continue to quarantine for 10 days – even if they are double jabbed – when restrictions on other amber list countries are eased.

Ministers said the move was a precautionary measure due to concerns over the “persistent presence” of the Beta variant in the country.

Where it has an advantage is that it is able to escape the immune response to a better extent

Prof Edmunds told the BBC’s Radio 4 Today programme: “The Beta variant has remained a threat throughout. It is probably less infectious than the Delta variant that is spreading here in the UK at the moment. Where it has an advantage is that it is able to escape the immune response to a better extent.”

He added: “As the population here becomes more and more immune, the conditions are right then for the Beta variant to get an advantage, so I can understand the concern.

“Of the variants that are out there and are known about, that one has always been a threat to us. There is some good evidence from South Africa that it can evade the immune response generated by the AstraZeneca vaccine more efficiently.”

The Oxford/AstraZeneca jab is among the four approved vaccines administered to millions of people in the UK in recent months.

From Monday, travellers returning to England from all amber list countries except France will not need to quarantine on arrival if they have been double vaccinated or are under the age of 18.

The France announcement underlines the uncertainty in some areas over the lifting of lockdown restrictions in England from July 19.

It also marks another hit to the fortunes of the travel sector, with industry body Abta saying it was a further setback for hopes of a “meaningful recovery”.

It also came just two days after the Spanish holiday islands of Ibiza, Mallorca and Menorca were moved from green to amber, meaning anyone over 18 who is not fully vaccinated must quarantine on their return.

Health Secretary Sajid Javid said the Government had always been clear it would take rapid action at the borders to “protect the gains made by our successful vaccination programme”, while Labour accused ministers of creating holiday “chaos”.

Shadow home secretary Nick Thomas-Symonds said: “Ministers are making up rules on the hoof and causing chaos.

“They have never had a proper strategy in place – once again the travel industry and the British people are paying the price.”

French tourism minister Jean-Baptiste Lemoyne tweeted on Saturday morning that France was adapting its border measures to require non-vaccinated travellers arriving from the UK, Cyprus, Spain, Greece, the Netherlands and Portugal to complete an antigen or PCR test less than 24 hours before departure. The change applies from midnight on Sunday.

However, travellers fully jabbed with a vaccine recognised by the European Medicines Agency – Pfizer/BioNTech, Moderna, Janssen and AstraZeneca – will no longer have to present a negative test in order to enter France, regardless of their country of origin.