This was Abadi's first effort to manage expectations for the reform programme he rolled out Sunday in response to widespread public anger over corruption and poor services.

"The process will not be easy; it will be painful. The corrupt will not sit by without lifting a finger," Abadi said in televised remarks a day after parliament signed off on his proposed measures.

Those who have "interests and privileges will defend their privileges and interests, and some of them will even fight for them," he said.

"They will try to sabotage each step we take".

The premier also said that, while some want him to make "unrealistic demands," he "will not demand anything that cannot be implemented."

The anti-corruption drive will be carried out without favour, including within his party, Abadi said.

"If there is a corrupt person in my party, I am against them, and if there is a good person in the party of my enemy, I am with him," he said.

Amid a major heatwave that has seen temperatures top 50 degrees Celsius (120 degrees Fahrenheit), protesters have railed against the poor quality of services, especially power outages that leave just a few hours of government-supplied electricity per day.

Thousands of people have turned out in Baghdad and cities in the Shiite south to vent their anger, pressure the authorities to make changes.

Their demands were given a boost on Friday when top Shiite cleric Grand Ayatollah Ali al-Sistani, who is revered by millions, called for Abadi to take "drastic measures" against corruption, saying the "minor steps" he had announced were not enough.

Various parties and politicians have sought to align themselves with the protesters in order to benefit from the movement and mitigate the risk to themselves.

Even with popular support for change, the entrenched nature of corruption and the fact that parties across the political spectrum benefit from it will make any efforts extremely difficult.

Iraq PM sacks senior cabinet official: statement
Baghdad (AFP) Aug 12, 2015 - Iraqi Prime Minister Haider al-Abadi has sacked a senior cabinet official who was a close aide to his predecessor and rival Nuri al-Maliki, the premier's office said in a statement Wednesday.

Abadi issued an "order to relieve the secretary general of the cabinet and his two deputies from their positions", the statement said, referring to Mohammed Khalaf Ahmed, who headed Maliki's personal office during his premiership.

The statement did not provide a reason for the dismissals, but the announcement comes during a major reform drive by Abadi aimed at curbing rampant corruption and streamlining the government.

Khalaf's responsibilities included providing advice and support to the premier, administrative services to the cabinet and managing state properties, according to a description of the post on a government website.

Maliki served two terms as prime minister and is widely viewed as having exacerbated sectarian tensions between the country's Shiite majority and Sunni Arab minority.

Widespread discontent among Sunni Arabs, who say they were marginalised and targeted by Maliki's government, played a major role in worsening the security situation in Iraq, culminating in a disastrous jihadist offensive last year.

Despite having the jihadist Islamic State group overrun a third of the country during his second term, Maliki nonetheless tried for a third.

But he stepped aside last August under major international and domestic pressure, ushering in Abadi's term in office.