The far-right Swiss People’s Party has admitted it is behind an advertising campaign that likens Roma migrants and Italians to rats.
Some sixty posters went up in the southern canton of Tessin, which borders Italy.
They show a Roma thief, an Italian worker and Italy’s Finance Minister Giulio Tremonti as rats nibbling at Swiss cheese.
The Swiss People’s Party or SVP is the largest single political party in parliament and part of Switzerland’s ruling coalition government.
Party official Pierre Rusconi said he had commissioned the campaign but said they reflected the real concerns of local people.
The adverts first appeared on Monday, but for days nobody claimed responsibility.
Italian MP Franco Narducci said he would be ask authorities to shut down all Internet sites and Facebook pages which published the poster.
The SVP has a reputation for provocative political campaigns.
It initiated a referendum on banning minarets last year, publishing pictures of burka-clad Muslim women with rockets strapped to their backs.