Frederiksen's idea is to form a government with the Radical Left and the Socialist People's Party.
But neither Venstre - a former government colleague of the Social Democrats - nor the moderate Lars Løkke Rasmussen’s Moderates support it.
"It risks drawing certain red lines that prevent us from doing what we believe Denmark needs," he tells TV2.
Frederiksen invited the Socialist People's Party, the Unity List, the Radical Left, the Alternative, the Moderates, the Liberal Party and the Conservative People's Party to the first talks after Tuesday's election.
