The imperturbable political system in Switzerland was facing its greatest challenge for 44 years after a lurch to the far right in Sunday's federal elections.
The country's mainstream parties of right and left have until 10 December to respond to demands by the anti-immigrant and anti-European Swiss People's Party for a second minister in the seven-strong federal cabinet.
Acceptance of the party's candidate, the billionaire populist Christophe Blocher, could harm Switzerland's placid image abroad. It could also upset the so-called magic formula of Swiss politics, which has hadcoalition governments since 1959.
Some mainstream politicians and political commentators said that having Mr Blocher in the next government could block the rise of a party whose appeal relied upon xenophobia and fear of crime. The Swiss system of government, powered by referendums and regional governments, would make it impossible for Mr Blocher to fulfil his populist promises, they said.
Excluding him would reinforce the belief that the political system was rigged in favour of the four "traditional" ruling parties. The newly elected lower house of the federal parliament must decide on 10 December how to fill the seven posts.
Mr Blocher has threatened that his party - now the largest in the country with 55 seats - will leave the coalition and go into obstructive opposition unless it is given a second cabinet post. Politicians of the left and right have accused him of blackmail and dictatorship.
Mr Blocher's party accused its mainstream rivals of allowing the economy to decline and taking a lax attitude toward immigrants - and especially asylum-seekers - who it claims are responsible for a crimewave.
For the first time, the People's Party - which began in German-speaking Switzerland - made serious gains in the French-speaking and Italian- speaking cantons, winning seven extra seats in the west and south of the country.
There were signs, though, that its popularity may have peaked in the German-speaking cantons. The People's Party lost a seat in its original Zurich heartland.Reuse content