Europe's migrant influx is the burning issue for Swiss voters electing a new legislature this weekend, with polls suggesting a boost for a nationalist party behind efforts to ban face-covering veils and construction of Muslim minarets.

Sunday's election is shaping up as a new sign of European anxiety about the influx of over a half-million migrants from Syria, Eritrea, Afghanistan, Iraq and elsewhere into Europe this year.

The vote to fill the two legislative chambers — the 200-seat National Council and 46-member Council of States — comes as a poll found nearly half of Swiss listed immigration, integration and foreigners as their top concern. Issues like relations with the European Union, health care, unemployment and the environment scored only single digits as the top issue.

Immigration is the sweet-spot of the nationalist Swiss People's Party, which wants to strengthen rules about who can enter and live — including from the EU member states that virtually surround the Alpine country of about 8.2 million people. A survey by the gfs.bern polling agency projects the nationalists getting about 28 percent of the vote, which would put it first in the constellation of Swiss parties.

If the election goes its way, the People's Party could land a coveted second seat in Switzerland's seven-person Federal Council, the executive branch that makes decisions by consensus and includes the national president — a rotating post. However, there is little chance that the nationalists could emerge as the leading party in a coalition government.

Switzerland hasn't faced a wave of migration like the one seen by some European Union states such as Germany and Sweden. But "the EU's problems with migrants" has fostered a "climate at the moment that helps the People's Party," said Lukas Golder, a gfs.bern political scientist.

The Swiss People's Party is the force behind a proposed ban on face-covering veils and a 2009 law prohibiting construction of minarets, which drew international condemnation.

One of Switzerland's main upcoming issues is the implementation of a narrowly adopted referendum calling for immigration caps on all types of foreigners, including those from the European Union, within three years. The result forced the government last year to take up the delicate task of revising its treaties with the 28-nation bloc, and has strained ties with Brussels.

Gfs.bern, in its latest survey published by the national broadcaster, found that the Swiss People's Party had the backing of 27.9 percent of respondents, which would mark an uptick of 1.3 percentage points from their tally in elections four years ago. The second-biggest party, the Social Democratic Party, came in at 19.2 percent, up half a percentage point from the last legislative election.

The free-market Free Democratic Party had the support of 16.7 percent, an increase of 1.6 percentage points. Smaller parties including the Green Party were expected to lose ground, the poll found.

The poll of 2,011 respondents was conducted Sept. 20-30 to include a representative sample from Switzerland's four linguistic regions. It has a margin of error of about 2.2 percent.