The agitating Madhesi Morcha, an alliance of seven political parties, on Tuesday night withdrew its support extended to the Pushpa Kamal Dahal 'Prachanda'-led government on expiry of its seven-day ultimatum, a Morcha leader said on Wednesday.
The deadline of the ultimatum to government ended on Tuesday midnight.
The Madhesi Morcha has now decided to sit in the opposition and said it would be announcing a series of protests.
The Morcha leaders have already written to Parliament Speaker Onsari Gharti, saying they were no more part of the ruling coalition, so they be allowed seats in the opposition row.
"We have withdrawn our support extended to the government, so allot us chairs in the opposition row," Morcha leader Mahendra Raya Yadav said in Parliament on Wednesday.
The Madhesi parties have 39 votes in Parliament, but their withdrawal will not have any immediate bearing on the coalition, as Prachanda still enjoys comfortable majority in the House.
Ahead of the installation of the Prachanda-led government in August 2016, the Morcha had extended support to the government after reaching a three-point agreement, including amendment in the Constitution to make it Madhes friendly and compensation to the victims of the Madhes uprising.
But the government, according to the Morcha leaders, failed to address the demands and understandings reached with Madhesi parties, forcing them to roll back their support.
A formal decision to withdraw support was expected to be taken by the Morcha later in the day.
After Morcha's ultimatum, Prime Minister Prachanda inducted the fourth largest party — Rastriya Prajatantra Party (RPP) — into the government to ensure the local polls slated for May 14 pass of without any hitches.
The Madhes-based parties have already announced a boycott of the local polls.
The Morcha felt betrayed by the current establishment after Prachanda proposed to amend the Constitution only after the local polls, citing the shortcoming of required two-third votes, according to the agitators.
Newly-inducted Deputy Prime Minister and RPP Chairman Kamal Thapa said on Tuesday that he joined the government after the Prime Minister assured that there would be no Constitution amendment.
Thapa is against the amendment and holds that if the amendment is put to voting in House, his party would vote against it and withdraw its ministers from the Cabinet.