When Iraqis go to the polls Sunday, they will vote for individual candidates rather than parties for the first time under a new electoral law meant to appease a youth-led protest movement fed up with the country's old-style politics.

In theory, the changes will strengthen local voices as candidates can now run at the district level and as independents, allowing new hopefuls such as tribal leaders, business people and civil society activists to join the race.

But the shadow of Iraq's traditional political blocs, which are mostly defined by religious sect or ethnic group, still hovers over many of the candidates who claim to be non-aligned, raising questions about the impact of the reform.

On campaign posters, many of the more than 3,200 hopefuls seeking office declare themselves to be free of affiliations with the powerful blocs in parliament -- but not everyone is convinced.

For many, it's simply an "electoral manoeuvre", argued political scientist Ihsan al-Shammari, saying they don't want to be associated with the entrenched forces widely blamed for inept governance, graft and shady backroom deal-making.

"The candidates want to distance themselves from the failures of their parties and try to adopt a new image, far from corruption and mismanagement," said Shammari of the Baghdad-based Iraqi Center for Political Thought.

Iraq is emerging from almost two decades of war and insurgency since the 2003 US-led invasion toppled dictator Saddam Hussein. Sunday's parliamentary election is the fifth since then.

But there is little popular hope for major change through the ballot box, and widespread disillusionment persists over the political caste as most Iraqis worry more about a painful economic crisis.