BAGHDAD, Iraq (CNN) -- Iraqi lawmakers on Sunday plan to take another shot at ending the impasse over a proposed election law -- a political crisis sparked by the veto of a newly passed measure this week by one of the country's leaders.
Leaders of the parliament's political blocs on Saturday reviewed a U.N. proposal to resolve differences over the measure and expect to take another crack at passing a bill again Sunday.
Lawmakers have been toiling for months in an attempt to pass legislation that would govern the machinery of national elections. They recently passed a compromise measure in an effort to avoid delaying January elections.
But a veto this week by Tariq al-Hashimi, the Sunni Arab vice president, threatens to ground major logistical preparations for the elections and could delay the polls.
It is a state of affairs that Iraqi and U.S. officials have been persistently trying to avoid, in part because it could upset the U.S. troop withdrawal timetable next summer.
Al-Hashimi says the bill is unfair to Iraqis who were forced to flee violence in their homeland. He refused to sign it without an amendment that would increase the number of seats allocated to refugees, many of whom are Sunnis, and small political parties that could not get enough votes on a national level. The numbers would increase from 5 percent to 15 percent.
After parliament's 275-member Council of Representatives passed the election measure November 8, it was passed to the country's three-member presidency council -- made up of Kurdish President Jalal Talabani, Shiite Vice President Adel Abdul Mehdi and al-Hashimi. For the bill to become law, it needed their unanimous approval.
Al-Hashimi's veto is rare because the passage of a bill usually means that it has the blessing of all the political blocs.