BERLIN - Chancellor Angela Merkel's chief of staff said on Sunday he fears the number of new coronavirus cases in Germany could soar to 100,000 a day in about two months unless many more people get vaccinated and those who refuse may face restrictions.

His suggestion quickly hit resistance from several senior politicians including Armin Laschet, conservative candidate to succeed Merkel as chancellor in a Sept. 26 election.

After more than two months of steady decline, COVID-19 cases have been rising in Europe's biggest economy since early July, due mainly to the spread of the more infectious Delta variant.

Merkel's chief of staff, Helge Braun, told Bild am Sonntag newspaper that cases were increasing by 60% per week even though nearly half the population is fully vaccinated.

"If the Delta variant were to continue to spread at this rate and we don't counter it with a very high vaccination rate or change in behaviour, we would have an incidence of 850 (per 100,000 people) in just nine weeks," he said.

That equates to about 100,000 new infections a day, he said, adding that would lead to many people having to quarantine and chaos in the economy.

Urging Germans to get vaccinated, Braun said those who refused might have to face some restrictions.

"This could mean some things such as restaurant, cinema and stadium visits would not be possible for tested unvaccinated people because the residual risk is too high," he said.

Roughly 60% of Germany's 83 million people have had a first shot of a COVID-19 vaccine and about 48% are fully vaccinated. Merkel has long said there will be no compulsory vaccination.

Braun's comment unleashed a debate with some politicians backing the idea and others, including Laschet, swiftly ruling it out.

"I don't think much of compulsory vaccinations or indirectly putting pressure on people," Laschet told ZDF television. "We have had a rule that you must be tested, vaccinated or recovered and I think that is a good principle," he said.

The Robert Koch Institute for infectious diseases said the number of cases had risen by 1,387 in the last day to 3.76 million. The seven-day incidence rate inched up to 13.8 per 100,000 people. Some 91,524 people have died of COVID-19 related causes in Germany.

(Reporting by Madeline Chambers Editing by Mark Potter and Susan Fenton) ((; +4930220133578;))