The development came as speaker Mohammed al-Halbusi suggested an agenda for an upcoming national dialogue session following an 11-month political paralysis that sparked deadly clashes in Baghdad last week.

"All parliament staff have returned to work," following orders issued on Saturday night, the parliament official told AFP, on condition of anonymity because he is not authorised to speak to the media.

"Operations in parliament had been suspended since protesters stormed the legislature's building," he said.

The protesters had staged a sit-in outside the assembly for weeks after initially storming it to demand fresh elections and the dissolution of parliament.

They pulled out last Tuesday at Sadr's orders following nearly 24 hours of violence pitting them against the army and Iran-backed factions that left more than 30 Sadr supporters dead.

The battles that started when Sadr supporters stormed the government palace in the capital's fortified Green Zone marked one of the deadliest episodes of street violence in the country in nearly three years.

In a statement posted on Twitter on Sunday, Halbusi suggested an agenda for a second national dialogue session, following a previous round that was held on August 17.

The dialogue sessions are part of a bid to end a political stalemate that has left Iraq without a new government, prime minister or president since elections last October.

The first session was boycotted by Sadr representatives.

Halbusi did not set a timeframe for the upcoming talks but said they should "set a date for early parliamentary elections" and discuss the election of a new president and formation of a government.

It was not immediately clear who would attend the talks.