Voters in Switzerland will decide on Sunday whether to become the first country to ban animal testing in a referendum that will also consider tightening controls on cigarette advertising.

Campaigners who want to end all experiments on mice, rats and other animals gathered enough signatures to stage the vote under the Swiss system of direct democracy, meeting strong opposition from the country's huge pharmaceutical sector.

The industry, which includes heavyweights Roche and Novartis, says such research is needed to develop new drugs.

Supporters of a ban on animal testing, which government data shows caused more than 500,000 animals to die in Swiss laboratories in 2020, say the practice is ethically wrong and unnecessary.

The most recent opinion poll showed 68% of respondents opposed the proposed ban, suggesting it is unlikely to be approved.

The proposal to further restrict tobacco advertising looks likely to pass, with 63% of people polled in favour.

Voters' answers will be binding on the government, which will then decide on how to implement the proposals.

The anti-tobacco campaign, which needs support from a majority of cantons and voters to pass, wants to extend the current curbs on advertising to cover adverts anywhere young people can see them.

This would include barring advertising in newspapers, cinemas, the internet, at events, and on billboards, with supporters saying such adverts encourage youth smoking.

The government says the proposed crackdown goes too far, and has come up with counterproposals that would further reduce advertising but still allow it in newspapers, shops and on the internet.

Also being decided on Sunday is a government proposal to abolish a 1% tax on equity raised by a company, a measure it says would reduce investment costs and support economic growth.

Opponents say scrapping the tax, which raises about 250 million Swiss francs ($270 million) per year, would benefit mainly large companies, with individual taxpayers left to make up the shortfall.

Financial support for Swiss media is the final issue to be considered by voters on Sunday. The government wants to avert the closure of more local newspapers and radio stations by granting an aid package of 151 million francs.

With slogans on posters saying "No taxpayers' cash for media billionaires", opponents have said the proposal would be a waste of public money and could threaten media independence.

The vote could go either way, with 49% against and 46% in favour, according to the latest polling data published by Swiss broadcaster SRG.