Ministers are “increasingly confident” that more countries will be added to the amber or green lists when the travel rules are reviewed next week.
Foreign Secretary Dominic Raab expressed optimism that more holiday hotspots could open up, saying “the momentum forward is positive”.
But he refused to rule out bringing in tougher rules for Spain amid fears it could be moved to the so-called “amber plus” list.
France was moved into the new category – which means double vaccinated people still have to quarantine – amid fears over the spread of the Beta variant.
And concerns are mounting over whether Spain could be put into this category or added to a watchlist, putting holidaymakers on notice that the rules could change.
The Government is expected to overhaul the travel lists next Thursday as part of a regular three-weekly review.