Three opposition parties in Ethiopia say they will boycott the forthcoming election in the Somali region.
Politician Joseph Nur says the pink card are stolen voter cards
They say their supporters have been harassed and thousands of voter cards stolen. Election officials have denied the accusations.
The vote is being held later than the rest of Ethiopia, which voted in May, due to security fears and problems reaching the Somali region's nomads.
The ruling party has already retained its majority in parliament.
"After observing the situation... we have all decided to boycott the election in the region in order to save our people from a disastrous fate," said a joint statement by the Western Somalia Democratic party, the Coalition of Somali Democratic Forces and Dall-Wabi People's Democratic Movement.
Joseph Nur, vice chair of the Western Somali Democratic Party, said: "At least 10,000 voter cards have been stolen and many are on sale in local markets."
ETHIOPIA'S NEW PARLIAMENT
EPRDF allies: 22
Still to be held: 24
Source: National Electoral Board
The Somali-based parties also accuse officials from the National Election Board of colluding with the government.
Voters in the 23 Somali constituencies are due to go to the polls on 21 August, along with voters in 32 other constituencies where irregularities were found.
At least five people were killed in grenade attacks in the Somali region last month, which have been linked to electoral tensions.
The ruling Ethiopian People's Revolutionary Democratic Front (EPRDF) already has 296 MPs - enough for a working majority in the 547-seat parliament.
However, the national opposition has also complained of electoral fraud and has threatened to go to court.
Despite their anger at the way in which the elections were held, the opposition parties will be greatly strengthened in the new parliament.
They now hold 174 seats - compared with just 14 in the last parliament.