"I expect a majority, up to two-thirds of eligible Iraqis to vote," interim President Ghazi al-Yawir said on Saturday.
But his comments came only hours after he said violence would deter the majority of Iraqis from voting.
"What we hope is that most Iraqis will take part in the election, but we know that the majority will not because of the security situation," al-Yawir said earlier.
"The majority will decide not to take part, not because they are boycotting the election, but because of the security situation," he added.
Al-Yawir, whose position is mainly ceremonial, also said any political process that did not include Sunnis, Kurds and Shia, Iraq's three main religious and ethnic groups, would be invalid.
'Following party line'
His latest comments, however, are more in line with those of Iraqi interim Prime Minister Iyad Allawi.
Iraqi interim leader Iyad Allawi
called on Iraqis to vote
"I ask them to participate in the elections whether they are inside or outside Iraq: Sunnis, Shia, Kurds, Christians," Allawi told Sky television in Baghdad. An estimated 14 million Iraqis are eligible to vote on Sunday in Iraq's first multi-party election since the 1950s.
Some groups, particularly the organisation allegedly headed by Abu Musab al-Zarqawi, have vowed to disrupt voting and stop people from going to polling centres.
About 6000 polling centres have been set up around Iraq, but the location of many is being kept secret until the last minute to minimise the risk they will be bombed.
Turnout is expected to be low, but the government has said it hopes for a national turnout of about 50%.
There has been a sharp increase in violence, including car bomb blasts, mortar attacks and shootings, this week as polling day approaches. The US military said attacks on US and Iraqi troops had tripled in the past seven days.