Hanspeter Rentsch, an executive director at the watch company Swatch, has warned that the referendum, and the poster propaganda, could damage Switzerland in the eyes of the world.

“The ‘Swiss’ brand must continue to represent values such as openness, pluralism and freedom of religion. Under no circumstances must it be connected with hatred, animosity towards foreigners and narrow-mindedness,” he said.

Campaigners demanded the referendum to halt “political Islamisation” by amending the Swiss constitution to add a clause stating “the construction of minarets is prohibited”.

Eveline Widmer-Schlumpf, the Swiss justice minister, has suggested that a vote for a ban could fuel Islamist radicalism and violent protests, such as those that greeted Danish cartoons of the Prophet Mohammed in 2006.

“This is not an appropriate instrument for combating religious extremism. It risks the opposite, of serving the cause of fanatics,” she said.

But Oskar Freysinger, an SVP MP, compares warnings of anger in the Muslim world to the arguments used by “appeasers” of Adolf Hitler and the Nazis.

“It is what Chamberlain thought in Munich in 1938. If these are the consequences, it is the proof that what we are doing to defend ourselves is legitimate,” he said.

The Telegraph