Speaking at a debate with Volker Kauder, head of the German CDU’s (Christian Democratic Union) parliamentary group, Leuthard said the German activists were like “the Taliban, who are trying to sabotage Zürich airport“.

Volker Kauder and his brother Siegfried, also a CDU politician, both live in Villingen-Schwennigen near the Swiss-German border and are among the most vocal critics of what they view as the excessive noise levels emanating from Zürich airport.

Leuthard’s comments elicited a strong reaction both in Germany and Switzerland after they were published in the media of both countries.

While in Germany her words were strongly criticised, in Switzerland many applauded her “clear language“, according to Tages Anzeiger newspaper, which has over 500 comments in its online forum.

“Finally a Swiss politician is speaking in the tone that is understood in Germany“, one commenter wrote.

Some commenters said they could see the funny side of Leuthard’s comment: “We have to laugh at these things.” To others, her “clear words” were “tactless, off-colour, and misplaced“.

Siegfried Kauder expressed outrage at the minister’s comment.

“Absolutely tasteless“, he told the Tages Anzeiger. “She has grossly insulted German politics with her comment.“

This is “neither normal political nor diplomatic speech“, he told Swiss newspaper Der Bund, adding that he wanted nothing more to do with the Swiss minister.

Leuthard has struck a nerve in the sometimes tense political relationship between Switzerland and Germany.

Local authorities in Waldshut, where the Kauders grew up on the Swiss-German border, informed the minister in a statement that “she should change her tune and pull in her horns”.

“In the heat of the Swiss election campaign, minister Leuthard should control herself,” according to the Waldshut statement.

Der Bund newspaper said the last signs from Berlin were that Germany wanted to come to an agreement with Switzerland about the airport row, but southern German politicians are sticking to their guns, according to Siegfried Kauder.

Studies have shown that southern Germany is much less affected by airport noise than the greater Zürich region, and Siegfried Kauder agreed that the level of noise pollution in his region varied:

“Sometimes one hears nothing, other times one thinks that a machine is landing in the garden. I can gladly invite you and wake you at 5am if you are not already awake,“ he told Der Bund.

The Kauders are supporting a petition that has so far garnered 80,000 signatures to have the number of flights over southern Germany curtailed.

14 percent of all passengers flying from Zürich airport live in Germany and many fly from Zürich on holidays or commute to Switzerland for work, 20 Minuten newspaper reports.