French President Emmanuel Macron confirmed plans to gradually reopen schools next week amid concerns from mayors, teachers and parents about the timing.

Macron, wearing a mask, visited a primary school in a suburb west of Paris on Tuesday that has remained open for children of health workers.

More than 300 mayors in the capital region, including Paris mayor Anne Hidalgo, urged Macron in an open letter to delay the reopening of primary schools scheduled for next week.

They denounced an “untenable and unrealistic timetable” to meet the sanitary and safety conditions required by the state, including class sizes capped to a maximum of 15. The majority of French children attend public schools.

Many parents say they won’t send their children back to school as France is one of the world’s hardest-hit countries by the coronavirus.

France starts lifting confinement measures on May 11, with businesses to resume activity and parents to return to work.