The centre-left Socialist Party has elected a new leader at an extraordinary congress in Basel.
Christian Levrat, a trade union leader and member of parliament, takes over from Hans-Jürg Fehr. He was the only candidate.
The party hopes that Levrat will be able to restore its fortunes after its relatively poor showing in the elections of October 2007, when its share of the vote dropped from 23 per cent to just under 20.
"We must stop the decline of the Socialist Party and win the 2011 elections," Levrat told delegates. He said the party had made mistakes in the 2007 campaign and failed to put across its policies.
He stressed the need for it to remember its roots as a mass social movement.
"Switzerland should rest on three pillars: social justice, a climate policy at the service of humanity, and openness to the world and to Europe," Levrat said.
He launched an attack on the unfairness of capitalist society, including the "indecent" salaries paid to some bankers.
A majority of activists who were polled for the congress blamed the party for not paying enough attention to issues which worried ordinary citizens, and for not reacting quickly enough to current events. They also felt it used language that was too "intellectual".
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