The Iraqi cleric whose bloc won the most votes in May’s election has called for a halt to talks to form a new government until the demands of protesters sweeping the south of the country are met.

Moqtada al-Sadr, a Shia cleric, whose bloc won the May election in a surprise upset for Prime Minister Haider Abadi’s coalition, had campaigned on alleviating poverty and improving services in the country’s Shia heartland.

But he appeared to undermine efforts to form a government on Friday when he backed the protests, which have raged in the oil-rich state of Basra for two weeks. At least three people have been killed in the unrest which saw protesters attack government and militia buildings, storm an airport in the holy city of Najaf, and gather outside an oil field.

It was not immediately clear whether Sadr’s comments amount to his bloc calling off the talks after he wrote on Twitter that factions "have to suspend all political dialogues for forming coalitions and until they meet protesters’ rightful demands".

The protests may be used by Sadr, who had backed previous demonstrations against the government, to gain an upper hand in the negotiations after the May 12 election marred by allegations of fraud. The talks have dragged on since, making little headway.

Mr Abadi, who is acting in a caretaker capacity until a new government is formed, has promised to boost electricity, health, and water services.

The prime minister had been hailed for leading a gruelling military campaign to expel Isis from much of the territory it held in Iraq after the jihadist group took over main cities in 2014.  With that mission largely accomplished , however, many Iraqis have turned their attention back to their daily hardships and poor government services.

Electricity in cities like Basra is sometimes cut for seven hours a day, while tap water is can be contaminated with mud. 

There had been protests in the south before but this month’s unrest has been more widespread. It comes at an especially sensitive time as Iraq’s competing coalitions try to form a government, with Mr Abadi hoping to be appointed again.

If the unrest continues and spreads, it could threaten to drive up oil prices, although exports have not yet been affected. The country exported 3.566 million barrels a day in July so far, Reuters reported.