At least three rockets hit Baghdad’s Green Zone on Thursday as a parliamentary session was about to meet to elect a new president and break a political gridlock.

The rocket attack came as the crisis-hit country makes its fourth attempt this year to elect a president more than a year after general elections.

Iraq is yet to form a new government to tackle the problems facing the oil-rich country plagued by unemployment, decaying infrastructure and corruption.

This week the United Nations mission warned that "the protracted crisis is breeding further instability" in the war-scarred country, and that the divisive politics are "generating bitter public disillusion".

If MPs elect a new president, a post now held by Barham Saleh, the new head of state would be expected to quickly nominate a prime minister who would seek to form a government to replace caretaker premier Mustafa al-Kadhemi.

Security was tight on Thursday, with police checkpoints and two bridges in Baghdad closed, creating traffic jams.

Lawmakers made three previous attempts to elect a new head of state, in February and March, but failed to even reach the required two-thirds threshold -- 220 out of 329 lawmakers -- for a quorum.

Two small opposition parties, totalling 15 MPs, have said they will boycott the vote Thursday.

Democratic institutions built in Iraq since the 2003 US-led invasion that toppled dictator Saddam Hussein remain fragile, and neighbouring Iran wields major influence.

For the past year, Iraq has not only been without a new government, but also without a state budget, locking up billions in oil revenues and obstructing much-needed reforms and infrastructure projects.

Under Iraq's power-sharing system, meant to avoid sectarian conflict, the state president by convention is Kurdish, its prime minister is a Shiite Muslim and the parliament speaker a Sunni.

30 candidates, three frontrunners

Iraq's rival Shiite Muslim political factions have been vying for influence and the right to select a new premier and form a government.

On one hand is the fiery cleric Moqtada Sadr, who wants parliament dissolved and new elections.

On the other sits the Coordination Framework -- an alliance of pro-Iran Shiite factions, including the former paramilitary Hashed al-Shaabi -- that wants a new government before fresh elections are held.

The standoff has seen both sides set up protest camps in recent months. Tensions boiled over on August 29 when more than 30 Sadr supporters were killed in battles between Iran-backed factions and the army.

It remains to be seen how Sadr will react: on Thursday, he posted a message on Twitter merely encouraging children on the start of the school year.

"It is still not clear that the Kurdish parties have come to an agreement on a president," said Hamzeh Hadad, a visiting fellow at the European Council on Foreign Relations think tank.

Among the 30 candidates, top contenders include the incumbent, Saleh of the PUK, aged 61, and current Kurdistan Interior Minister Rebar Ahmed of the KDP, aged 54.

Abdel Latif Rashid, 78, a former water resources minister and PUK leader, is running as an independent.

Next step, new PM

Once elected, the president will nominate a prime minister who needs the backing of the largest bloc in parliament and who then begins arduous negotiations to choose a cabinet.

"What is expected is that whoever is chosen will designate a prime minister right away to form a government," said Hadad.

Key runners for prime minister include the Coordination Framework's candidate, former minister Mohammed Shia al-Sudani, 52.

Hadad believes Sudani is the most likely to be premier, but noted that "anything can change in Iraqi politics till the last minute".

The pro-Iran Coordination Framework draws together the Fatah alliance and lawmakers from the party of Sadr's longtime foe, former prime minister Nuri al-Maliki.

When Sudani was proposed in July, it sparked mass protests by outraged Sadr supporters, who breached the Green Zone and stormed parliament.

(FRANCE 24 with AFP and Reuters)