Madhesi parties have rejected the new constitution amendment bill introduced by the government.
A meeting of the Madhesi Front, an alliance of seven Tarai-centric parties, also decided on Wednesday to boycott local elections slated for 14 May.
The bill was registered in the Parliament secretariat by the ruling coalition on Tuesday.
The Front dubbed the new bill 'more regressive' than the previous one, which was withdrawn from the House on Tuesday itself.
The Federal Alliance, which is protesting alongside the Front, will decide later today whether to accept the new proposal. It too is likely to reject it.
The new bill proposes a permanent high-level commission to redraw federal boundaries, and amends constitutional provisions on language and citizenship.
Prime Minister Pushpa Kamal Dahal has claimed that the new bill was introduced after consultations with Madhesi parties and the main opposition UML. But neither side has endorsed the bill.
Madhesi parties have welcomed the proposal to form a federal commission but have slammed the government for withdrawing the previous bill without having provincial boundaries readjusted.
The UML has welcomed withdrawal of the previous bill, which redrew federal boundaries. But it has not supported the new one, and instead urges the government to now focus on local level elections.
With Madhesi parties rejecting even the new bill, their participation in local elections remains unlikely.