This is in response to a deal forged in South Africa between the government of Joseph Kabila and the Ugandan-backed former rebel group, the Movement for the Liberation of Congo.

DR Congo has been engulfed in a civil war for almost four years and Mr Kabila is being kept in power by troops from Zimbabwe and Angola.

A ceasefire was signed in Lusaka in 1999 but sporadic fighting has continued and correspondents say there are now fears that the conflict may reignite.

'Coup d'etat'

The RCD's leader, Adolphe Onusumba, told the BBC's Network Africa that the new group was formed to bring the government and the MLC back to the negotiating table.

He described the deal, under which Mr Kabila remains president and the MLC's Jean-Pierre Bemba becomes prime minister, as a "coup d'etat".

Onusumba's group has a strong hand to play with large parts of DR Congo under its control

"We are on the legal side. They are the ones who spoiled what the Congolese were expecting," he said.

The RCD is the largest rebel group in the DR Congo and controls around a third of the country, which is the size of western Europe.

Under the Lusaka accord, all Congolese rebel groups and political parties were supposed to thrash out a new political dispensation with the government, leading to the country's first ever elections.

Dictator

This "Inter-Congolese Dialogue" has been taking place in the South African resort town of Sun City over the past eight weeks.

The deal between Mr Kabila and the MLC was announced just before the talks were set to close last week.

The new grouping, called the Alliance for the Protection of the Inter-Congolese Dialogue, ASD, warned against a potential "partition of the DRC and resumption of conflict".

Mr Tshisekedi enjoys some support in the capital, Kinshasa, after spearheading opposition to the former dictator, Mobutu Sese Seko for many years.

Other parties involved in the ASD are:

• Rafael Katebe Katoto's Dynamic for a Neutral Transition
• the United States-based Rally for a New Society
• the Congolese National Movement-Lumumba
• Lumumbist Progressive Movement