German neo-Nazis are under fire for producing state-funded election campaign posters emblazoned with the slogan “step on the gas”, words that have been widely seen as an “inhumane” reference to Nazi death camps.

The electioneering materials, produced for Berlin state elections in September, depict Udo Voigt, the leader of the Germany’s far-Right National Democratic Party (NPD) sitting on his motorcycle.

Smiling and wearing a black leather jacket Mr Voight’s hand grips the his bike’s throttle with the words “gas geben”. The phrase normally means, “step on it” or speed up but has much controversial associations for a party closed linked to neo-Nazis.

Andreas Gram, a senior Christian Democrat politician in Berlin, attacked the “right-wing extremist” NPD for openly making an “association with the gas chambers” that killed millions of Jews in Nazi death camps.