Hundreds of people have protested in Geneva at a campaign by the canton's rightwing Swiss People's Party that brands workers from a French border town as "scum".
A half-page advertisement appeared in the Tribune de Genève newspaper on Monday saying a proposed CEVA regional rail link to Geneva was "a new way of transporting the scum from Annemasse". It also calls for foreign criminals to be deported.
Unia, the main Swiss union, leftwing Geneva parties and unions from the French region of Rhône-Alps converged in the Place Neuve in Geneva on Thursday night carrying placards calling for an end to "border worker racism".
The mayor of Annemasse, Christian Dupessey, announced he would be making an official complaint and said the People's Party had crossed a line, using a xenophobic approach to "incite hatred".
"Some things are not acceptable in political debate," he said, adding that of the 60,000 workers who crossed the French border around Lake Geneva into Switzerland daily, 20,000 were Swiss.
swissinfo.ch and agencies