Iraq's parliament has amended an election law that was vetoed by a Sunni Arab vice president, but Sunnis say the changes do not address their concerns.

The dispute highlights ethnic and sectarian divisions in Iraq, and could force a delay in national polling scheduled for January.

Vice President Tariq al-Hashemi vetoed the law because he wants more seats for Iraqis living abroad, most of whom are Sunnis.

Lawmakers voted Monday to change the system for distributing seats. But lawmakers from the Sunni minority walked out before the vote, saying they will lose seats under the change.

Al-Hashemi is likely to veto the amended law, but parliament can override a second veto with a three-fifths majority.