Iraq's parliament has approved May 12 as the date for holding national elections despite calls from the country's Sunni community to delay the vote until the return of nearly 3 million people displaced by the fight against the Islamic State group.

Shiite lawmaker, Abbas al-Bayati, says the legislative body "unanimously" approved the date, which was proposed by the government, at Monday's session.

The deeply-divided parliament failed many times to set the date, prompting the country's Supreme Court to issue a ruling on Sunday against any further delay.

The over three-year-old fight against IS has left most of the Sunni areas in northern and western Iraq in ruins, and poor public services have exacerbated the situation.

The elections will be the fourth since the 2003 U.S.-led invasion that toppled Saddam Hussein.