Conservative groups are threatening to block Switzerland from hosting next year’s Eurovision by forcing budget referendums on potential host cities, saying the song contest is a “propaganda event” that “celebrates satanism and occultism”.

Switzerland won the right to host the world’s largest live music event after the Swiss singer Nemo triumphed in Sweden with The Code. The cities of Zurich, Geneva, Bern and Basel have all filed applications to host the five-day spectacle.

The Christian conservative Federal Democratic Union of Switzerland (EDU) party, however, has said it will seek to make use of the country’s direct democracy system to put the bidding cities’ loan applications to the vote.

“The Eurovision song contest is a ghastly propaganda occasion”, the EDU said in a social media post on Tuesday. “A country that provides a stage to such disgusting trash won’t elevate its image but merely showcase its own intellectual decline.”

Samuel Kullmann, a senior EDU politician, told the Swiss broadcaster SRF his party was disturbed by Eurovision’s increasing “celebration, or at least tolerance of … satanism and occultism”. “More and more artists present openly occultist messages and underline them with respective symbols,” he said.