The Federal Supreme Court decided "to suspend the work" of influential Sunni MP Mohammed al-Halbussi on a temporary basis, while it investigates the process of his election.

The move impacts the workings of parliament, as lawmakers cannot meet without the speaker.

One of parliament's first tasks must be to elect the country's president, who will then name a prime minister tasked with forming a new government

Despite Halbussi's suspension, the clock has not stopped ticking on the 30-day deadline to elect a new president that began at the parliament's inaugural session, the court said.

Iraq's post-election period since the October 10 vote has been marred by high tensions, violence and allegations of vote fraud.

In multi-confessional and multi-ethnic Iraq, the formation of governments has involved complex negotiations ever since the 2003 US-led invasion toppled dictator Saddam Hussein.

Parliament only met Sunday for the first time in three months since the polls, where the new members held a swearing-in ceremony and elected the speaker.

It opened to furious arguments between rival factions of Shiite lawmakers.

Amid the debate, Mahmud al-Mashhadani -- the oldest member of parliament who was therefore chairing the opening session -- was taken ill and rushed to hospital.

When the parliamentary session resumed an hour later, lawmakers re-elected as speaker Halbussi, from the Sunni Taqadom party.

The vote however was boycotted by the Coordination Framework, a key Shiite bloc.

The appeal against the speaker's election was filed by Mashhadani, as well as another MP, Bassem Khachan.

Key arguments have been held between rival Shiite blocs, each claiming to a majority able to appoint a prime minister.

Shiite cleric Moqtada Sadr, who once led an anti-US militia and who opposes all foreign interference, has repeatedly said that the next prime minister will be chosen by his movement.

It won the largest share with 73 out of the assembly's 329 seats, more than a fifth of the total.

But the Coordination Framework, including pro-Iran groups such as the Fatah (Conquest) Alliance, the political wing of the pro-Iran ex-paramilitary coalition Hashed al-Shaabi, insist their grouping is bigger.