Emile Ilunga - leader of the main grouping of the splintered Congolese Rally for Democracy (RCD) - told the Reuters news agency that he backed the truce which is aimed at stopping a year-long civil war.

"We are ready to sign the ceasefire," he said.

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"We are signing not as a matter of weakness, but to give peace a chance in our country and to allow for the creation of a new political order through dialogue."

Both rebel forces and President Laurent Kabila's government have received help during the conflict from neighbouring countries.

Six African countries involved in the war in DR Congo signed a peace accord in Lusaka in July.

However, the RCD did not add its signature because of an internal power struggle between Mr Ilunga and the leader of another faction of the RCD, Ernest Wamba dia Wamba.

Mr Wamba dia Wamba was ousted as overall leader of the RCD earlier this year, but has continued to receive backing from Uganda and insists he is still in charge.

Neither Mr Ilunga nor Mr Wamba dia Wamba could agree on who had the authority to sign the agreement.

Allies clash

The rivalry between the two men led to a clash in the Congolese town of Kisangani between Rwandan and Ugandan troops, who are backing different factions of the RCD.

However, under a compromise mediated by South Africa and Zambia, all 50 founding members of the RCD - including the rival leaders - will sign the ceasefire.

Jean-Pierre Bemba, leader of the Congolese Liberation Movement (MLC) - another rebel organisation involved in the war - has already signed the peace accord.

Tuesday's signing is due to be overseen by regional foreign ministers, UN officials and Zambian president, Frederick Chiluba.

Under the ceasefire, a Joint Military Commission is due to work out the deployment of UN peacekeepers and supervise all-party talks.

"We are ready for all these things, provided Kabila and his allies follow the rules and play fair game," Mr Ilunga told Reuters.

"But we are also ready for whatever eventualities that may emerge. One cannot trust Kabila," he said.