Nepal braced Monday for months of political instability and street protests after parliament missed its Sunday midnight deadline to complete the task of writing a new post-war constitution.

Nepal's Prime Minister Baburam Bhattarai said Sunday the Constituent Assembly had failed to achieve its goal. He said he will stay in office until the new polls, scheduled for November 22, take place to elect a new assembly.

The government placed security forces in the capital, Katmandu, on “high alert” after demonstrators clashed with police outside the parliament building Sunday.

The Constituent Assembly, created in 2008 after the abolition of Nepal's centuries-old Hindu monarchy, was tasked with drafting the constitution. The lawmakers' tenure was extended four times, but the Supreme Court rejected any further extensions.

The four main parties were attempting to resolve differences over whether new states to be created by the constitution will be drawn on the basis of ethnicity. Opponents of the idea said it could fuel more unrest.

Last November, Nepal's main political parties agreed to a deal to integrate thousands of former Maoist fighters into the army, a move seen as bolstering the peace process.

Maoist rebels were allowed to join the government after a 2006 peace deal ended their decade-long insurgency that claimed more than 13,000 lives.