Nepal’s interim parliament began to debate on Thursday a motion by Maoists to immediately abolish the monarchy, as the government vowed to defeat the move in a row that has shaken the country’s peace process.

The impasse has already led to the former rebels quitting the government and to the postponement of constituent assembly elections, casting a shadow over a peace deal reached last November, ending a 10-year civil war that caused 13,000 deaths.

The Maoists have called for the declaration of a republic and for a switch to full proportional representation in planned elections to an assembly to draw up a new constitution.

Prachanda, the Maoists’ chief, has threatened they could bring down the government if it does not agree to their demands. Analysts say the Maoists still have the power to disrupt the country with large street protests and strikes.

The motion is expected to be put to a vote next week.

Maoists have 83 out of 329 seats in the body.

“We don’t believe that the constituent assembly elections are possible without the declaration of a republic,” Krishna Bahadur Mahara, the Maoist leader in parliament said at the opening of the debate.

Peace and Reconstruction Minister Ram Chandra Poudel called the motion “unconstitutional” and asked the Maoists to withdraw it.