Senior political leaders and the Maoists in December 2006 finalised an interim constitution that opened doors for the former rebels to join the government.

The document, signed by Prime Minister Girija Prasad Koirala and rebel leader Prachanda, was to be approved by parliament before taking effect.

However the constitution has not been placed before the legislature since it was signed and the rebels contend the government is stalling by saying that a UN-monitored arms agreement must be in place first.

"We are very much concerned by the delay as the government is not serious enough to pass the interim constitution," Maoist spokesman Krishna Bahadur Mahara told AFP Wednesday.

"It has raised doubts if the planned constituent assembly elections could be held on time. This could give room to anti-democratic elements to plot against the elections," Mahara said.

But the government denied the Maoists' accusations.

"We are waiting for the arrival of the initial group of UN arms monitors by mid-January. Once they become operational the interim constitution will be passed immediately," said Ramesh Lekhak, a government negotiator and minister for labour.

"The government is committed to hold elections to a constituent assembly within the stipulated time," said Lekhak.

The two sides reached agreement on a power-sharing pact following mass protests April 2006 that led King Gyanendra to return power to parliament after 14 months of direct rule.

The rebels and the new parliament subsequently agreed to a ceasefire and a political process leading to election by June 2007.

The minister said that the government has already directed the Election Commission to update voter lists as part of preparation for the upcoming polls.

The temporary basic law is due to remain in force until the June 2007 elections for a constituent assembly that will rewrite the constitution permanently and decide the monarchy's fate.

Under the peace deal, agreed in November last year, the government has agreed to let the Maoists have 73 seats in a new 330-seat parliament in return for placing their arms and armies in camps under United Nations supervision.