Germany's new Left Party, which polls show will win 12 per cent next month's general election, draws on a concept of 'National Socialism' from the Nazi era, a prominent German historian alleged on Wednesday.

"This is not an accident - it's intentional," said Goetz Aly who recently published a book arguing that Hitler's Nazis won allegiance by creating a huge social welfare state funded by property stolen from the Jews and people in Third Reich-occupied Europe.

A leader of the Left Party, a rebel former Social Democratic (SPD) chairman Oscar Lafontaine, said in a speech last month that German workers had to be protected to prevent foreigners
stealing their jobs.

"The state is obligated to prevent family fathers and women from becoming unemployed because 'Fremdarbeiter' (foreign workers) are taking away their jobs by working for low wages," said Lafontaine at a rally in the eastern German city of Chemnitz near the Czech border.

Germany's Brockhaus dictionary says the term 'Fremdarbeiter' is a Nazi expression used to describe foreign and often slave labour brought to Germany during World War II.