As Iraq inches towards civil war amid political infighting and growing sectarianism, one figure stands out as the nation's potential saviour, or nemesis: radical Shi'ite leader Moqtada al-Sadr.
Just 32, anti-American to the hilt, closely linked to extremist groups in the Middle East and backed by a personal militia, Mr Sadr's strength is rooted not in political savvy or negotiating skills, but his impeccable religious credentials: He can trace his ancestry directly to the founder of Islam, the Prophet Mohammed. In a country where everything from electricity to security has failed, that counts for a lot.
In recent weeks, though, he has gained a nation-wide voice that none will challenge for fear of unrest spinning out of control at his say so.
In Baghdad today, Mr Sadr will lead a rally uniting Shi'ites, who comprise 60 per cent of the country's population and wield real political power, and Sunnis, one-fifth of Iraqi's population and the former rulers under ousted dictator Saddam Hussein. A big turnout would cement his increasingly apparent position as Iraq's foremost political force.
Respect - or perhaps more likely, fear - for his authority was the reason Vice-President Adel Abdul Mahdi broke a weeks-long deadlock on Wednesday and signed a presidential decree allowing parliament to meet. He has set in motion the process for the formation of the country's first democratically elected government.
Mr Sadr's followers won 30 of the 275 parliamentary seats in the December election, and his backing enabled Prime Minister Ibrahim al-Jaafari to win the nomination of the Shi'ite bloc for a second term. But the outbreak of sectarian violence between Shi'ites and Sunnis after a sacred Shi'ite shrine was bombed on February 22 in the town of Samarra provided him with an opportunity he was quick to exploit.