The Delta variant now accounts for around 20% of all Covid cases in France, Health Minister Olivier Véran said this morning (June 29).
This is up from an estimated 9-10% of cases last week.
Mr Véran told FranceInfo Radio the variant was “gradually becoming dominant” in France “as it does in all countries in the world, as it is more contagious”.
The World Health Organisation has said the variant is now present in 85 countries.
Portugal was the first EU country to declare that the Delta variant had become the dominant strain, accounting for 51% of all cases nationally and 70% of cases in Lisbon.
Some health restrictions have been reintroduced in the worst-affected areas as a result, such as limiting hours and capacity for restaurants and shops.
Germany has also said that new Covid cases caused by the Delta variant have doubled in the past week.
Overall cases in France still going down
In France the rise in cases of the Delta variant has not yet caused a rise in the number of Covid cases overall.
The national incidence rate (meaning the number of cases per 100,000 inhabitants in the past seven days) is still falling.
On June 28, the national average for the number of cases in the past seven days reached one of the lowest figures in the past 10 months at 1,819 cases, compared with a peak in April of 42,225.
This means that the 20% of Covid cases caused by the Delta variant currently accounts for a relatively small number of cases overall.
On Monday, 509 new Covid cases were reported nationally during the previous 24 hours.
But Mr Véran said data from England, where the variant is also dominant, indicated the downward trend could change.
“There were 23,000 Covid diagnoses linked to the Delta variant in England [on Monday],” he said.
“This means we must proceed with humility and vigilance.”
The health minister also called for “vaccination on a massive scale” to limit the potential effects of the spread of the Delta variant in France.