A change in the balance of power in the Swiss government is unlikely when parliament votes for a new cabinet minister on December 4.
In all probability Ruth Dreifuss will be replaced by another Social Democrat - one of the party's official candidates.
A convention dating back to 1959 - commonly known as the "Magic Formula" - ensures that there is a representative balance in government between the country's different political and linguistic blocks.
"As far as replacing Dreifuss is concerned it will be a Social Democrat," political analyst, Hans Hirter, told swissinfo. "And when it comes to government policy, little will change."
But such inevitability of the outcome does not give the Social Democrats the right simply to appoint a minister. The party has had to go through a selection process and - insofar as it can - present a ticket that will ensure one of the official candidates is elected.
"In other countries a minister is just a minister," says Hirter. "But here in Switzerland every cabinet minister is at least one seventh of a president.
"They all have the same rights and they all have the same strength of vote."
In addition to holding a ministerial portfolio each member of government spends a year in office as president on a rotating basis.
While the structure of the cabinet may not change this year, many political pundits and politicians see the cabinet vote as a precursor to a possible power struggle after next year's parliamentary elections.
The Swiss People's Party - which according to recent opinion polls could be the single largest parliamentary party after the October ballot - is looking to accelerate its demands for an extra seat in the cabinet.
The People's Party only has one seat - something it says no longer reflects its current status as the second largest party overall.
It has also been the largest party of the right since the last election in 1998. But according to Hirter that position still needs to be confirmed next year before any realistic challenge to the makeup of the cabinet can be made.
Although the People's Party candidate stands no chance of being elected to the cabinet this time around, Hirter says the nomination of a candidate is a tactical move to show the electorate that there is only one true party of the Right.
"That is a clear message the People's Party wants to get across to the electorate ahead of next year's [national] election," he says.
"Especially as the centre-right Christian Democrats and Radicals will join forces with the Social Democrats to elect one of the leftwing candidates."
The real turning point should come in December next year when the entire cabinet will have to stand for re-election - as it does every four years.
Hirter thinks both Christian Democrats and the newly elected Social Democrat could find their seats under threat. He says it will depend on how the parliamentary Radicals decide to vote. They traditionally hold the balance of power.
Even though one of their cabinet members, Kaspar Villiger, is expected to stand down next year, Hirter does not think the party will have a problem replacing him from within its own ranks.
"On the one hand they are strong enough to merit two cabinet seats," he says. "On the other hand no coalition can be formed without them.
But expect the unexpected could be the motto for any election of a new cabinet member as the vote to replace Dreifuss will be taken by a secret ballot.
There is no guarantee that either of the proposed Social Democrat candidates will result in being the parliamentary choice.
The election of Dreifuss in 1993 bears testament to that. She was not her party's first choice, and did not become the official candidate for a cabinet seat until parliament had first turned down the number one contender and then seen the winner of the vote, Francis Matthey, stand down in favour of a French-speaking woman.
Micheline Calmy-Rey may be the frontrunner, but Ruth Lüthi cannot be discounted and anyone else could launch a challenge on the day. Hirter says we must not forget the importance of the vote being a free one.
"Someone may throw their hat into the ring and do unexpectedly well," he says. "And those voting may decide to switch their allegiances.
"It is especially hard to predict who is going to win - but that is what makes politics interesting."
swissinfo, Jonathan Summerton
The Social Democratic Party has nominated two official candidates to contest the vacant cabinet seat.
The magic formula guarantees a political and linguistic balance in the government.
Under the magic formula outgoing Social Democrat, Ruth Dreifuss should be replaced by a politician from the same party.
The vote is a free one conducted by a secret ballot of all members of parliament.
The new cabinet minister will have to secure at least half the available votes plus one.