Police raids on neo-Nazi groups in Germany last week could boost efforts to ban the country’s biggest far-right party.

The raids turned up incriminating material including 1,000 election posters for the far-right National Democratic Party of Germany (NPD), which has an estimated 7,000 registered members.

The NPD is legal, but the three extremist groups subjected to raids last week were banned the same day that 900 police closed in on them.

The groups are located in North-Rhine Westphalia, which held elections over the weekend. Security agents estimate that between 400 and 600 right-wing activists live in the state.

Interior Minister Ralf Jaeger called the banned groups “xenophobic, antisemitic, and a danger to peaceful coexistence”. They include the Comradeship of the Region of Aachen, the National Resistance Dortmund and the Comradeship Hamm.

The discovery of NPD posters with one of the groups fuels the argument that the NPD feeds off smaller, violent collectives. Mr Jaeger told Stern magazine that an NPD ban will be discussed in December with Federal Interior Minister Hans-Peter Friedrich.