Eight days after the media exposed a meeting between AfD members and neo-Nazis discussing a plan to expel foreigners or people of foreign origin from Germany, members of the Bundestag spent more than two hours discussing the defence of democracy in a country that bears the scars of Hitler's horrors.

"It is right and necessary for the Office for the Protection of the Constitution to keep a close eye on the AfD," said Social Democratic Interior Minister Nancy Faeser.

"Anyone who dreams of 'reconquest' and 're-immigration' is in line with the inhumane racial laws of the National Socialists and the ideas that paved the way for the Shoah at the Wannsee Conference (where the final solution for the Jews was agreed)," Nancy Faeser said to applause.

"None of this is harmless," the interior minister warned, "and you can be sure that we will use all the tools of our brave democracy, the tools of criminal law and association bans, to fight the AfD." Faeser promised to "dry up the funding sources of this circle".

The revelation of the meeting in November in Potsdam, near Berlin, came as a shock to the country at a time when the AfD was enjoying record polling figures of between 21 and 23 percent nationally.

In the former East German states of Saxony, Thuringia and Brandenburg, where crucial regional elections are due to take place in the second half of the year, the racist party even exceeded 30 percent.

Thousands of people have demonstrated in defence of democracy in recent days in cities across Germany, including Berlin, Cologne and Freiburg.

In Potsdam, where the meeting was held about three months ago, about 10,000 people marched last weekend, including Social Democratic Chancellor Olaf Scholz and Green Party Foreign Minister Annalena Baerbock.

More and more people, especially from the Social Democratic Party, are calling for the AfD to be banned.