George Eustice, the environment secretary, claimed the move was not necessary – despite the UK itself currently requiring 10-day isolation on return from all EU destinations.
“I don’t think such a move would be justified, but obviously it’s for individual countries to make these judgments,” he told LBC Radio.
The row comes after the German Chancellor called for a united EU approach, after rocketing cases of the Delta variant in the UK put it at the top of the table for Covid infections.
“In our country, if you come from Great Britain, you have to go into quarantine – that’s not the case in every European country and that’s what I would like to see,” Ms Merkel told the Bundestag.
The German leader intervened as the British government prepares to relax its rules for returning holidaymakers, probably in time for the school holidays at the end of July.
The Balearic Islands, Malta and some Caribbean islands could be added to the ‘green list’ today – lifting the need for isolation and expensive tests, which are making holidays unviable for many families.
And, even more significantly, fully vaccinated Britons – and their children – would be able to travel to amber list countries later this summer without quarantine or testing on return, under government plans.
The German call complicates those moves, but Mr Eustice pointed to “the highly advanced stage” of the UK’s vaccination programme, with 80 per cent of adults having had one jab and 60 per cent both doses.
Greece and Spain are among Mediterranean sunspots that have broken with Brussels to allow in British travellers without requiring them to isolate.
But that openness is threatened by the UK’s failure to keep the Delta – or Indian – variant under control, with 16,135 new confirmed cases on Wednesday, the highest figure since early February.
In just a few weeks, the UK has gone from the European country with the lowest Covid rate to having the highest – amid fierce criticism of Boris Johnson for failing to shut off travel from India in time.
The Delta variant is now dominant in Portugal, has emerged in clusters in Germany, France and Spain and is expected to account for 90 per cent of all EU cases by the end of August.
Germany only accepts Britons for “humanitarian reasons”, such as a family bereavement, and has mandatory 14-day quarantine for any Germans travelling from the UK.
Italy followed suit on Monday by imposing a five-day quarantine on British travellers until at least July 30 because of concern over the delta variant.
The US currently bans UK tourists and its top infectious disease expert, Dr Anthony Fauci, has signalled the US is unlikely to open a travel corridor with the UK before September.