One of the biggest parties in the Democratic Republic of Congo will boycott the first multi-party elections in 40 years, it says.
UDPS supporters had demanded that voter registration be extended
The announcement by the Union for Democracy and Social Progress (UDPS) comes a day after registration to contest the polls ended.
The electoral commission is to announce the new date for the polls. They had been set for June but were put back.
The elections are supposed to end a transitional period after a civil war.
UDPS spokesman Jean-Baptiste Bomanza said it would boycott the elections peacefully because basic conditions for a transparent vote had not been met.
More than 70 people have registered to contest the presidency, including the incumbent, Joseph Kabila.
Two vice-presidents and former rebel leaders, Jean-Pierre Bemba and Azarias Ruberwa, have also submitted their papers and paid the non-refundable $50,000 registration fee.
President Joseph Kabila
Vice-President Jean-Pierre Bemba, former rebel leader
Vice-President Azarias Ruberwa, former rebel leader
Catherine Nzuzi wa Mbombo, standing for Mobutu's PRM party
Pierre Pay Pay, ex-finance minister and central bank governor under Mobutu
UDPS leader and veteran opposition figure Etienne Tshisekedi did not register.
The BBC's Arnaud Zajtman in Kinshasa says the boycott raises the likelihood of election violence, as Mr Tshisekedi has considerable support among the poor residents of the capital, as well as in his home region of Kasai.
Mr Tshisekedi last year urged his supporters to boycott voter registration saying the polls were not free. He then changed his mind but the electoral commission refused to reopen voter registration.
Some 4,000 candidates have now registered to be members of the 500-seat parliament.
UN Secretary General Kofi Annan recently said the polls pose "major logistical challenges, if not nightmares".
After years of war and misrule, there is little infrastructure in a country the size of Western Europe.
There are no road or rail links from one side of the country to the other, which has made it difficult for parliamentary candidates to get to Kinshasa, where they are required to register to stand in the elections.
DR Congo's infrastructure has been wrecked by war and misrule
The world's largest United Nations peacekeeping force - nearly 17,000 troops - is tasked with ensuring the elections go smoothly.
The EU's German-led force will be deployed shortly before the polls and will stay for up to four months.
Some 450 soldiers will be based in Kinshasa with another 1,000 on standby outside DR Congo.
In the east of the country, hostilities between rival militias and government forces continue to force hundreds of thousands of displaced people from their homes.