The UN Mission in Nepal (UNMIN) has formally objected to plans by the opposition Maoist party to include members of its army in an upcoming political conference, a spokesman said Friday.
Nepal's Maoists fought a 10-year civil war against the state before agreeing to lay down their arms in a 2006 peace agreement and transforming themselves into a legitimate political party.
But thousands of former fighters in the Maoist People's Liberation Army (PLA) remain in UN-monitored cantonments around Nepal pending a final decision on whether and how they should be integrated into the national military.
Reports say around 1,000 of these plan to attend the meeting, due to start on Sunday in the northern town of Gorkha.
"(UNMIN chief) Karin Landgren wrote a letter expressing her concern about the participation of army personnel in the Maoist plenum," UNMIN spokesman Kosmos Biswokarma told AFP.
"She urged the Maoists and the other parties to refrain from any activities that could have a negative impact on the peace process."
The party meeting -- the largest gathering of the former rebels since they laid down their arms -- is being held at a sensitive time for Nepal, which has been without a functioning government for nearly five months.
More than a dozen votes to try to elect a new prime minister have failed and the resulting political stalemate has delayed the peace process and the drafting of a new constitution in the impoverished Himalayan nation.
The PLA defended the plan, saying the meeting would include debate on the future of the former combatants.
"The party cannot take any decision on our future without allowing us to participate in the debate,"