Switzerland votes Sunday on whether to ban full facial coverings in public places, despite women in Islamic full-face veils being an exceptionally rare sight in Swiss streets.

Polls indicate a slim majority supports the move, in a vote that comes after years of debate following similar bans in other European countries -- and in some Muslim-majority states.

Even though the proposal "Yes to a ban on full facial coverings" does not mention the burqa or the niqab -- which leaves the eyes uncovered -- there is no doubt what the debate concerns.

Campaign posters reading "Stop radical Islam!" and "Stop extremism!", featuring a woman in a black niqab, have been plastered around Swiss cities.

Rival posters read: "No to an absurd, useless and Islamophobic 'anti-burqa' law".

The ban would mean that nobody could cover their face completely in public -- whether in shops or the open countryside.

There would be exceptions, including for places of worship.

"Besides being useless, this text is racist and sexist," said Ines El-Shikh, spokeswoman for the Purple Headscarves feminist Muslim women's group.

She told AFP that the proposed law created the impression of a problem, but "there are only 30 women in burqas in Switzerland".

A 2019 Federal Statistical Office survey found that 5.5 percent of the Swiss population were Muslims, mostly with roots in the former Yugoslavia.

- 'Extreme' Islam concerns -

The full-face veil "is an extreme form of Islam," said Yes campaign spokesman Jean-Luc Addor, of the populist right-wing Swiss People's Party (SVP).

He acknowledged that "fortunately" there are not many burqa-wearing women in Switzerland, but stressed that "when a problem exists, we deal with it before it gets out of control".

The government and parliament oppose a nationwide ban.

Their counter-proposal -- automatically triggered if the initiative is rejected -- would require people to show their faces to the authorities if necessary for identification, for example at borders.

Under Switzerland's system of direct democracy, any topic can be put to a national vote as long as it gathers 100,000 signatures in the wealthy country of 8.6 million people. 

Rounds of votes take place every three months.

To pass, initiatives require support from a majority of voters nationwide, and from a majority of federal Switzerland's 26 cantons, six of which count as half-cantons in votes.

A 2009 vote that banned the construction of minaret towers on mosques sparked anger abroad.

- Indonesia trade, e-ID votes -

Two other votes are being held Sunday.

One is on the free trade agreement struck between Switzerland and Indonesia.

Tariffs would be gradually removed from almost all of Switzerland's biggest exports to the world's fourth most populous country, while the Swiss would abolish duties on Indonesian industrial products.

Opponents, who are especially critical of Bern's move to reduce import duties on palm oil, successfully secured a popular vote on the deal.

A February poll for Tamedia newspapers found 52 percent backing the deal, with 42 percent against.

The other vote is on a government plan to introduce a federally recognised electronic identity, that could be used for ordering goods and services online.

The idea is that the e-ID would be regulated by law, offering a degree of security and reliability when giving identity details on the internet. It could also be used to open a bank account or request an official document.

Recent polls suggest that a comfortable majority is opposed to the move. It was pushed to a popular vote by critics alarmed at the plan to rely on private firms for the IDs, giving them access to sensitive, private information.

Though most votes will have been cast in advance, polling stations will be open for a few hours on Sunday.

Polling stations will close at midday (1100 GMT), with initial results expected by early afternoon.