Defence Minister Samuel Schmid says Swiss cabinet ministers face an increasing number of threats and need police protection.
He said he deplored the erosion of a culture which is marked by political tolerance with people of different opinions.
Schmid added the threats had to be taken seriously and called on politicians not to fuel tensions – a statement seen as a hint at some members of his rightwing Swiss People's Party.
The new justice minister, Eveline Widmer-Schlumpf, was the latest target of death threats and hate mail after she accepted her election to the cabinet earlier this month.
She unseated the controversial Christoph Blocher – the strongman of the People's Party – prompting an apparent rift between radical and more moderate members of the party.
Observers have described the campaign to October's parliamentary elections as unusually divisive, culminating in clashes during a demonstration in the capital, Bern.