DR Congo opposition anger over electoral changes
Opposition parties in the Democratic Republic of Congo have strongly criticised government plans to elect the president in one round of voting.
The parties said the proposal had "the sole aim of organising electoral fraud on a grand scale" to keep President Joseph Kabila in power in November.
The BBC's Thomas Hubert in Kinshasa says the opposition has never before adopted such a united position.
The government say the changes would avoid an explosive confrontation.
The presidential elections in 2006 were the first democratic polls in DR Congo for four decades.
But in the second round, the vote was split between the east and west of the country, sparking violence in the capital, Kinshasa - where the losing candidate had support.
President Kabila's camp announced at the beginning of January that it intended to modify the constitution to avoid the risk of such a confrontation.
Our reporter says the president's supporters also want to get rid of proportional representation to build a stronger parliamentary majority.
But the opposition wants the electoral laws to be kept intact and described any attempt to revise them as a dangerous step backward.
"President Joseph Kabila's initiative to revise the constitution and consequently the electoral law... is inappropriate," AFP news agency quotes Francois Mwamba of the Movement for the Liberation of the Congo (MLC) as saying.
"[It] has the sole aim of organising fraud on a grand scale and of allowing a single individual to confiscate all state powers."
As the electoral law stands at the moment, if no candidate wins with more than 50% of the vote in November, a second round will be held in February 2012, the agency reports.