Iraqi electoral officials say they've suspended preparations for elections in January until a new election law is approved.
One of Iraq's vice-presidents, Tareq Al-Hashimi, has vetoed part of the election law.
Mr al-Hashemi, who is a Sunni Arab, revoked Article 1 of the law and called for the representation in parliament of displaced people to increase to 15%, the BBC reports.
He says he objected to the section of the legislation because it did not give voice to the four million Iraqis, mostly Sunni Arabs, whom he believed had fled the country following the sectarian conflict triggered by the US-led invasion in 2003.
The law was passed by parliament 10 days ago, after a long delay, and will now have to go back to legislators for further discussion.
Mr al-Hashimi says he thinks this can be dealt with quickly and need not delay the elections.