Parlament will debate on Tuesday a motion for a no-confidence vote in the government of Prime Minister Boyko Borisov filed by the Bulgarian Socialist Party, the Movement for Rights and Freedoms and independent MPs last week over what they say is "the failure of the government in the area of justice and home affairs".
The motion, which was signed by 74 MPs of the 240-seat Parliament, needs 121 votes to pass.
The right-wing Democrats for Strong Bulgaria (DSB) will not back the motion and will call on its partner in the Blue Coalition, the Union of Democratic Forces, to boycott the debate, the state-run Bulgarian News Agency (BTA) quoted DSB deputy leader Radan Kunev as saying on Monday.
Far-right party Ataka, however, will not support the government. Its leader Volen Siderov called on the cabinet to step down and a new coalition government to be set up.
The motion will be put to the vote on Wednesday, 24 hours after the end of the debate.