A far-right party that is part of Switzerland's ruling coalition said Friday it was behind an advertising campaign that likened Roma migrants and Italians to rats. An official with the Swiss People's Party (SVP) said it was behind posters showing three rats representing a Roma thief, an Italian worker and Italy's Finance Minister Giulio Tremonti nibbling at a piece of Swiss cheese. The SVP, the largest single political party in parliament, is part of Switzerland's ruling coalition government. About 60 posters went up in the southern canton of Tessin, which borders Italy, criticising the presence of 40,000 Italian workers and 'foreign criminals', according to an accompanying website. The adverts first appeared on Monday, but for days nobody claimed responsibility, prompting speculation the campaign could be the work of a smaller political party or even a businessman seeking to promote Swiss cheese. 'It's a campaign about the things the people in the canton are suffering from,' Pierre Rusconi, the local leader of the party, told reporters. Rusconi said the party had remained silent during the controversy because 'nobody would be interested in the adverts if the (party) had given its name'. 