Iraq's interim rulers say the National Guard (ING), currently spearheading anti-insurgency activity, is to be dissolved and merged with the army.
Iraqis view the ING as ill-disciplined and an easy target
The merger was originally planned for much later, after ING defeated the insurgency with the help of US forces.
It will now take place on 6 January, the defence minister said on Wednesday.
No reason was given for the change, but it may be a way to improve recruitment as the ING is seen as ill-disciplined and an easy target for insurgents.
The paramilitary ING, which is responsible for internal security, has more than 40,000 troops, according to figures given to the United Nations by US forces occupying Iraq.
The regular army is thought to number barely one tenth of that.
But the ING has lost hundreds of personnel in daily attacks by forces opposed to the US military presence in Iraq.
A National Guard general narrowly escaped a suicide car bombing outside his home in Baghdad on Tuesday.
Violence has increased in the run-up to US-backed national elections set for 30 January.