Iraq’s cabinet approved a wide-ranging reform plan on Sunday that would abolish the three vice-presidential posts as well as the office of deputy prime minister in order to slash spending and improve the government’s performance in the face of mass protests.

Prime minister Haider al-Abadi’s plan, which still requires parliamentary approval, would effectively sack his predecessor, Nouri al-Maliki, who begrudgingly stepped aside a year ago and was appointed to the largely symbolic role of vice president. Al-Maliki is widely alleged to have undermined his successor in a bid to eventually return to power, charges he denies.

Al-Abadi’s seven-point plan would also require that a number of government posts be filled with political independents, a move aimed at combatting endemic corruption in Iraq’s political system, in which many senior appointments are determined by party patronage and sectarian loyalties.

A year after assuming office following Islamic State’s rapid advance across northern and western Iraq, al-Abadi is still struggling to combat the extremist group.

But he is now also facing a wave of discontent over government services. Iraqis have been suffering a brutal heatwave with frequent power cuts, leading to mass protests even among the Shia majority from which the government draws most of its support.

Al-Abadi’s plan would reduce spending on personal bodyguards for officials and transfer the responsibility to the interior and defence ministries, which would have their budgets expanded.

The plan also calls for the review of all corruption cases by a committee of experts, with fresh trials for officials suspected of wrongdoing.

The proposed reforms come two days after Iraq’s most revered Shia cleric, grand ayatollah Ali al-Sistani, called on al-Abadi to quickly address internal issues in the government, including corruption. Through his spokesman Ahmed al-Safi, al-Sistani said the prime minister must be more “daring and courageous” in his steps to reform the government, urging him to strike “with an iron fist anyone who is tampering with the people’s money”.