"We see what is coming from the right parties. They desperately want to weaken Nynorsk if they have the power to do so," Liv Signe, minister for local government, said in an interview with Bergens Tidninge.
Her comments came as the country's 600,000 Nynorsk speakers celebrate the 200th anniversary of the birth of Ivar Aasen, the 19th century lexicographer who first argued for the predecessor to Nynorsk to be treated as a separate language.
To mark the day, Bergens Tidninge, the newspaper for the city of Bergen, the centre of the country's Nynorsk speakers, published the day's edition in Nynorsk instead of its usual Bokmål.
Nynorsk has enjoyed equal status with the more dominant Bokmål form of Norwegian since 1885.
Around 12 percent of Norwegians, predominantly on the west coast around Bergen, speak Nynorsk, and 26 percent of the country's 114 municipalities have declared Nynorsk their official language.
But Signe said she wanted to enshrine the language's status in the Norwegian constitution to prevent right-wing moves to undermine its equal status.
The Conservative Party denied plans to downgrade the language.
"To say that we want to 'detonate a bomb' is just one more thing to add to the file of the gross violations made by the red-green coalition in their discussions of Conservative Party policies," said Elisabeth Aspaker, the Conservative party's Education Policy spokesperson.
Ivar Aasen, born 5 August 1813, in Sunnmøre, on Norway's west coast, was a gifted linguist who more or less singlehandedly constructed a new "people's language' or 'folkemål' for the country.
His Dictionary of the Norwegian Dialects, published in 1848, was crucial in the establishment of Norwegian as a literary language, ending the situation where a great Norwegian writer such as Ibsen would compose his plays in Danish.