However, Abdul Hussein Hindawi, the head of the Independent Electoral Commission in Iraq, said on Tuesday it was still awaiting a full list from the interior ministry and the US-led forces of the detainees who should be allowed to receive ballots and vote on Saturday at Abu Ghraib prison and several other US detention centres.
"All non-convicted detainees have the right to vote. That includes Saddam and other former government officials. They will vote," Hindawi said.
Saddam's long-awaited trial is scheduled to begin on 19 October on charges that he and seven of his top lieutenants ordered the 1982 massacre of 143 people in a mainly Shia town north of Baghdad following a failed attack on Saddam's life.
More than 12,000 detainees are being held at the notorious Abu Ghraib prison, Camp Bucca and two other US military camps in Iraq, many awaiting trial or, in some cases, formal charges.
Many of the detainees are believed to be Sunni Muslim Arabs who were rounded up by US and Iraqi forces on suspicion of supporting anti-government groups.
Also in the capital, fighters on Monday opened fire on a convoy carrying delegates from the Arab League in Baghdad during its first visit to Iraq since the fall of Saddam. A policeman was wounded in the shooting, but no one in the delegation was hurt.
An Arab League delegation is
meeting with resistance in Iraq
However, the head of the delegation, Arab League Assistant Secretary-General Ahmed bin Heli, denied any such occurrence.
The league has met resistance from Shia Muslim and Kurdish leaders as it tries to piece together a reconciliation conference with Sunni Muslims.
Across Iraq, fighters are currently demanding that Iraqis boycott the referendum and have killed at least 340 people in the past 16 days in a series of attacks, including car bombs, roadside bombs and drive-by shootings.
That included a US soldier and six Iraqis who were killed in Baghdad on Monday by a bomber who detonated a car full of mortars near an entrance to the fortified Green Zone, where Iraq's parliament and the US embassy are located.
Whether the constitution passes or fails, Iraq is due to hold elections for a new parliament on 15 December.