Paul Charles, CEO of the PC Agency, has said data suggests Italy, Germany, Poland and Canada could all be added to the green list.
Mr Charles said: “Spain’s infection rate appears to be flatlining and falling. So I would expect a continued reduction by this time next week.”
However, many travel experts fear holiday hotspots such as Spain and Greece could be moved to the amber plus list due to the rise of Beta variant cases.
Both countries have increased lockdown restrictions in recent days and weeks in a bid to keep on top of the virus.
The movement of Spain and Greece to the amber plus category could mean as many as six million Britons have their holiday hopes dashed.
Greece has recorded 178 COVID-19 cases per 100,000 over the past seven days, while Spain has recorded 385 per 100,000 – up 10 percent week-on-week.