Nuri al-Maliki may be in pole position to remain Iraq's prime minister, but allegations of malpractice during last month's polls are clouding the prospect of forming a government anytime soon.

Key rivals of the premier, from inside and outside his Shiite community, allege irregularities at the polling stations, as well as problems with the transport of ballot boxes and vote counting, potentially delaying the certification of results, or even changing final tallies.

Maliki's bloc emerged from the April 30 vote with by far the most seats in parliament, nearly three times as many as his nearest opponent, though his State of Law alliance fell short of an absolute majority on its own.

That means he will need to court support from rival blocs, many of whom have publicly said they will not countenance a third term for a prime minister they allege has consolidated power and is responsible for deteriorating security.

"By Thursday (May 22), we had received 30 complaints from candidates and parties," said Mohsen al-Mussawi, a board member on Iraq's election commission.

Mussawi said at least three major parties had submitted challenges.

They were the Sunni Arab Mutahidoon bloc of parliament speaker Osama al-Nujaifi, the secular Sunni-backed Wataniya party led by ex-premier Iyad Allawi, and the Shiite Muslim Citizens grouping that is seen as close to Iran.

The complaints will be considered by a committee of senior judges, who will then rule on their validity. No firm timeline has been set for the process.

All three parties, and several others, have said they will not support a third term for Maliki.

Following 2010 elections which saw him finish a narrow second to Allawi's now-defunct Iraqiya bloc, the premier called for, and successfully obtained, a manual recount of all votes that meant final results were not certified until months after ballots were cast.

Though the results remained the same, Maliki later managed to out-manoeuvre Allawi to secure backing for a national unity government under his leadership, with a cabinet eventually being sworn in nine months after elections.

- Reversal of Fortunes -

In a reversal of fortunes from the last elections, Allawi is now among those calling for a manual nationwide recount.

"I call on political leaders to stand seriously against counterfeiting," he said in a statement. "I demand a manual recount and punishment for all those who have hurt the democratic process."

His Wataniya bloc have alleged that the election commission was under the sway of "powerful political parties", and blamed it for "clear biases."

Nujaifi, meanwhile, said in his own statement that Mutahidoon had observed "many violations", while a spokesman for the Citizens bloc has also alleged malpractice.

"Power and state finances were used in the election campaign to win votes," the party's spokesman Daligh Abu Gilal told AFP. "A huge amount of land was distributed to citizens and promises of jobs were made by candidates who are in power."

"All of these are clear violations."

The premier stands accused of consolidating power, particularly within the security forces, and the opposition blames him for a year-long deterioration in security and say the quality of life has not improved enough.

Voters also often complain of poor electricity and sewerage services, rampant corruption, high unemployment and a litany of other concerns.

Maliki, however, has urged his rivals to accept the results and diplomats have called on the country's political leaders to begin work towards forming a government.

Iraq's political parties have already begun meeting and manoeuvring as they seek to build post-election alliances, but forming a new government could still take months.

As in previous elections, the main blocs are expected to agree on an encompassing package that ensures the prime minister, president and parliament speaker are all selected together.

Under a de facto agreement, the prime minister is a Shiite Arab, the president is a Kurd and the speaker of parliament is a Sunni Arab.

"The result of the election should be accepted transparently, and in the spirit of forgiveness," Maliki said in his most recent weekly televised address.

"We should not listen to suspicious accusations here and there."