The opposition March 14 movement, led by former Prime Minister Saad Hariri, announced plans to boycott the administration led by Prime Minister Nijab Mikati.
Mikati, in a statement published by The Daily Star newspaper, said stepping away from the political process was no way to address national problems.
"National issues are not resolved via stubbornness, arrogance or reactionary stances but through dialogue in order to develop common goals shared by Lebanese to fortify the nation under these dangerous regional circumstances," said Mikati.
The Syrian civil war has threatened to spill into Lebanon. A mid-October car bombing in Beirut killed former Lebanese intelligence chief Brig. Gen. Wissam al-Hasan, an attack March 14 officials blamed on Damascus.
The opposition slate announced a total boycott of the Mikati government but said it wasn't an act meant to bring down the government or its allies in Hezbollah.
"The battle is to face the dangers that beset Lebanon and that cannot be faced by a government which lost the confidence of the majority of the Lebanese," a March 14 statement read.
Lebanon, the opposition coalition said, "is in danger."