A top Maoist leader in Nepal says the rebels would have to respect the decisions of a constituent assembly if elections to it were "free and fair".
Maoist rebels are fighting for a communist republic
Senior rebel leader Baburam Bhattarai told the BBC the assembly would also have to have sovereign powers to decide on the fate of the monarchy.
Creating an assembly to draft a new constitution is a key rebel demand.
On Sunday, MPs backed elections for the body, less than a week after the king recalled parliament following protests.
'Verdict of the people'
Mr Bhattarai welcomed the establishment of the assembly.
"We think this is a step forward in our democratic movement, but it's still worryingly ambiguous," he said.
"It's not clear whether the constitutional assembly would be conditional or unconditional - that means whether it will be sovereign, free to decide on anything including the abolition of the monarchy, or the continuation of monarchy.
"Our point of view is that it has to be a sovereign constituent assembly which can decide on the abolition of monarchy, and an institutionalised democratic republic."
"If the elections are free and fair, one has to respect the result of the elections. Then of course we will abide by the verdict of the people. But we don't believe that the verdict will go in favour of the king."
Correspondents say that if Mr Bhattarai's latest comments are shared by his group, they would represent a significant step towards a political compromise.
The Maoists have fought for more than a decade to establish a communist republic and want the monarchy abolished.
Pradip Giri of the Nepali Congress Democratic Party - one of the seven parties which led protests against the king - said the Maoists need have no worry about the assembly's powers.
Nepali MPs were meeting for the first time in four years
"There should be absolutely no doubt in their minds, or in the minds of the public, that the constituent assembly will be competent to abolish the monarchy if it decided to," he told the BBC.
Parliament set no date for elections to the assembly when it met on Sunday.
The move came after new Prime Minister Girija Prasad Koirala was sworn in by King Gyanendra - who ended direct royal rule after weeks of protests.
Mr Koirala, 84, was too ill to be sworn in on Friday when parliament reconvened for the first time in four years on Friday.
In an address to MPs, Mr Koirala urged the Maoist rebels to renounce violence and join peace talks immediately.
More than 13,000 people have died in the insurgency.
The BBC's Charles Haviland in Kathmandu says it is little wonder that peace talks are top of the agenda now because any elections would be difficult given the violence in the countryside.