More than half of the presidential candidates in Democratic Republic of Congo's landmark elections, due this month, have called for a postponement.
President Joseph Kabila is the favourite to win
Twenty of the 33 candidates say the elections are being badly organised and question why an extra 5m ballot papers have been printed.
The United Nations is helping to organise the polls, which follow five years of conflict.
The east remains unstable - some 5,000 people have fled their homes recently.
They have fled fighting in the north-eastern Ituri province, seeking refuge in the capital, Bunia, after rebels seized the town of Tchei, 80 kilometres (50 miles) away.
The world's largest peacekeeping force - 17,000 troops - is trying to ensure that the elections pass off peacefully.
DR CONGO'S ELECTIONS
33 presidential candidates
8,650 parliamentary candidates
500 parliamentary seats
267 registered political parties
25m registered voters
50,000 polling stations
The UN hopes they will be DR Congo's first democratic elections in 45 years.
"There are too many ballot papers and the process is not transparent," said Scientific Research Minister Gerard Kamanda Wa Kamanda, one of the 20 unhappy candidates.
"Many people will come to the streets and demonstrate to show they are opposed to not credible elections in this country."
National Independent Electoral Commission chairman Apollinaire Malu Malu said it was logistically easier to send the same number of ballot papers to each of the 50,000 polling stations and this was why some 5m extra ballot papers had been printed.
KEY PRESIDENTIAL CANDIDATES
President Joseph Kabila
Vice-President Jean-Pierre Bemba, ex-rebel leader
Vice-President Azarias Ruberwa, ex-rebel leader
Vice-President Arthur Z'ahidi Ngoma, ex-rebel leader
Pierre wa Syakassighe Pay-Pay, ex-minister known as 'Mr Cash'
Francois Joseph Nzanga Ngbangawe Mobutu, son of former leader
Catherine Marthe wa Mbombo Nzuzi, ex-minister, standing for another faction of Mobutu's party
Vice-President Jean-Pierre Bemba, a former rebel leader and one of the front-runners, is not joining the calls for a postponement but does want the extra papers to be returned to the capital, Kinshasa, and destroyed.
The BBC's Arnaud Zajtman in Kinshasa says the capital's streets are now covered in election posters - mainly for President Joseph Kabila, Mr Bemba and another former rebel chief, Vice-President Azarias Ruberwa.
The largest rebel groups joined a power-sharing government as part of the 2002 deal to end five years of conflict.
The UN mission in DR Congo, has meanwhile said the expulsion of a French radio reporter gave out "a very bad signal" ahead of the polls.
Ghislaine Dupont from Radio France Internationale (RFI) was deported for working without official accreditation.
"We are all very worried," said Monuc spokesman Kemal Saiki.
"RFI is an important organ which has a very large audience in the African continent - to deprive African listeners of the possibility of informing themselves of the progress of the election campaign is extremely regrettable."
He also said the authorities were "racketeering" by demanding payment of up to $500 for press accreditation.
In Ituri, UN forces have used armoured vehicles and fighter helicopters to halt the rebel advance, the peacekeeping mission said.
Monuc has been helping the Congolese army to disarm rebels ahead of the polls in Ituri and other parts of the east.
After years of conflict and misrule, holding the vote will be a major challenge - there are no roads or railways linking one side of the country to the other.