Germany's incoming chancellor Olaf Scholz on Tuesday signalled his backing for mandatory coronavirus jabs, a party source told AFP, as the country struggles to contain a fierce fourth wave of the pandemic.

Scholz, who is holding crisis talks with regional leaders, said he was "aware that there were cross-party debates" among lawmakers about making the vaccine compulsory, a source at the meeting said.

"Scholz signalled his sympathy for such a regulation," added the source, who is from Scholz's centre-left Social Democratic Party (SPD).

The introduction of mandatory jabs would have to be approved by parliament.

Outgoing Chancellor Angela Merkel's conservative CDU/CSU bloc, which will not be part of Scholz's incoming ruling coalition, has also come out in favour of requiring citizens to be inoculated against Covid-19.

Scholz, Merkel and the heads of Germany's 16 states are discussing tougher curbs to confront record-high infection rates and rapidly filling intensive care beds.

Among the measures being discussed are the closures of bars and clubs, and limiting large events.

Several hard-hit German regions have already cancelled Christmas markets and barred the unvaccinated from public spaces like gyms and leisure facilities.

But critics say the patchwork of rules is confusing, and Tuesday's emergency talks are aimed at coming up with more uniform rules for the whole country.

According to German media, Scholz has told participants at the talks that he is in favour of barring the unvaccinated from more parts of public life, including non-essential retail.

- Court backs shutdowns -

The mulling of harsher measures comes just hours after Germany's constitutional court ruled that sweeping restrictions imposed earlier in the pandemic to stem infections -- including curfews, school closures and contact restrictions -- were lawful.

Helge Braun, Merkel's chief of staff, told the RTL broadcaster the court decision indicated "which of two paths we should go down".

The country recorded 45,753 new infections on Tuesday and 388 deaths, according to the Robert Koch Institute health agency.

Hospitals have long been sounding the alarm, with many already over capacity and sending patients to other parts of Germany.

To tame the surge, Europe's biggest economy has over the last weeks began requiring people to prove they are vaccinated, have recovered from Covid-19 or have recently tested negative before they can travel on public transport or enter workplaces.

Germany's vice-chancellor-in-waiting Robert Habeck on Tuesday called for tougher restrictions to slow the spread of the disease.

"What has to happen is absolutely clear: contacts must be reduced," the co-leader of the Green party said, also calling for unvaccinated people to be banned from "all public facilities" apart from essential shops.

"We will need new uniform measures to get through the winter," Habeck said, also urging Germany's federal states to apply the "range of options" they already have, such as cancelling Christmas markets.

"This is then -- it must be said so harshly -- a lockdown for the unvaccinated," he said.