By Joshua Franklin
ZURICH (Reuters) - Swiss voters will face decisions on whether to deport foreign lawbreakers to building a second tunnel through the Gotthard mountain range when they go to the polls on Sunday.
Switzerland holds referendums several times a year under its system of direct democracy in which voters can deliver their verdict on proposed legislation and public initiatives which gain the necessary 100,000 signatures of support.
The hot issue on Sunday is a proposal from the anti-immigration Swiss People's Party (SVP) on whether to subject any foreign resident to automatic deportation if convicted of a crime as serious as murder or an offense as minor as speeding.
Under the SVP's draft law, foreigners would be automatically deported after completing their sentences for serious crimes like murder, rape and armed robbery, or for two lesser offences committed within a 10-year span such as speeding or burglary.
A 'yes' vote for could further complicate relations with the European Union, Switzerland's biggest trading partner, as it tries to reconcile another SVP-sponsored measure for quotas on EU workers with Brussels.
Polling from research group gfs.bern, though, sees voters in the famously wealthy and orderly Alpine republic narrowly rejecting the latest anti-immigration proposal.
Some opponents have even put up posters depicting the cross on Swiss flags as a swastika.
"The mobilization against the proposal is very strong," said Patrick Emmenegger, political scientist at the University of St. Gallen. "Turnout is likely to be very high (by Swiss standards)."
Polls also show voters rejecting a proposal to ban trading in agricultural derivatives, a measure the government opposes.
Campaigners aim to fight world hunger by prohibiting banks, trading houses, insurers and other investors in Switzerland from dealing for themselves or for clients in financial instruments based on agricultural commodities or food.
Banning such trade would harm the economy, impinge on economic liberties and raise questions about Swiss policies at a time Switzerland is struggling with the impact of a strong currency, the government has argued.
In the two other referendums, gfs.bern polling shows 53 percent back campaigners seeking to abolish a tax disadvantage for married couples and civil partnerships.
Some 56 percent support adding a second road tunnel through the Gotthard, a main north-south transit route. Opponents have complained about the added traffic and noise as well as the environmental impact.
(Editing by Richard Balmforth)