Nepal's former communist rebels plan to block the budget in Parliament to press their demand for a change in government, a spokesman said on Tuesday.
The stoppage announced by Communist Party of Nepal (Maoist) spokesman Dinanath Sharma is likely to spark another crisis in this Himalayan nation.
The fiscal year ends July 16, and the government would be unable to function if next year's budget is not presented by then. The budget session is scheduled to start July 5
The Maoists have been protesting for more than a year to demand the present coalition government be disbanded and replaced by a Maoists-led government.
They shut down the nation for a week last month. There was an agreement that Prime Minister Madhav Kumar Nepal would resign but so far he has not.
The Maoists fought for 10 years against government troops until 2006 when they gave up their armed revolt to join mainstream politics. They have confined their fighters in U.N.-monitored camps and won the most seats in elections in 2008.
They briefly led a coalition government but it ended over the firing of the army chief, leading to the current coalition.