The first results from Sunday's vote were not expected for until Tuesday, he said, but the State of Law coalition, led by Nouri al-Maliki, the incumbent prime minister, claimed to be leading in nine of Iraq's 18 provinces.
"The State of Law Coalition list is leading among other lists in Baghdad and other southern provinces," Ali al-Dabbagh, a government spokesman and candidate for the Shia State of Law bloc, said.
"But the special voting and voters abroad, this has not been concluded yet and could alter the outcome," he said.
Most Iraqis abroad are believed to be minority Sunnis.
Al Jazeera's Mike Hanna, reporting from Baghdad, said the first preliminary result, to be announced in the coming days, would be based on just 30 per cent of the votes and may not be that representative of the actual vote.
"But the count will continue and while it does, the political manoeuvring will begin, all the parties seeking among each other who they could ally themselves with," he said.
"The prime intention is to get a governing bloc within the parliament which has 50 per cent plus one seat, which would then enable that particular bloc to form a government and nominate a prime minister."
Al-Maliki's bloc was was ahead in Shia regions, while Iyad Allawi, the former prime minister who heads the Iraqiya list, was leading in Sunni areas, according to estimates the AFP news agency obtained from officials across the country.
Thaer al-Naqeeb, an Iraqiya candidate and close aide to Allawi, said results were not clear so far but he said Iraqiya got between 70-90 per cent of votes in the northern and western provinces.
Meanwhile the Supreme Islamic Iraqi Council (ISCI), which is one of the Shia parties grouped in the Iraqi National Alliance (INA), said the vote appeared evenly split between al-Maliki's bloc and INA in early counting.
On Sunday, Iraq's electoral commission urged Iraqi political parties to wait for the announcement of official results before declaring victory.
Final results, certified by the supreme court after hearing appeals, were expected within about a month of the election.
More than 6,000 candidates from 86 political groups were competing for the 325 seats in parliament.
The general in charge of US troops in Iraq said on Monday that the election was a "milestone" on the way to a full pullout of US combat troops.
General Ray Odierno told reporters in Baghdad that most of the about 96,000 troops currently in Iraq will remain until May, when the military would begin scaling down to 50,000 non-combat troops by September.
The timetable calls for all troops to be out by the end of 2011.
"Unless there's a catastrophic event, we don't see that changing," Odierno said.
Despite tight security arrangements, the vote was marred by violence as a series of explosions left at least 38 people dead and 89 others wounded in the capital.
The bloodiest toll was from an explosion that destroyed a residential building in the Shaab district of northern Baghdad, killing 25 people and wounding at least eight more.