Iraq's insurgency counts more than 200,000 active fighters and sympathisers, the country's national intelligence chief told AFP, in the bleakest assessment to date of the armed revolt waged by Sunni Muslims.

"I think the resistance is bigger than the US military in Iraq. I think the resistance is more than 200,000 people," Iraqi intelligence service director General Mohamed Abdullah Shahwani said in an interview ahead of the January 30 elections.

Shahwani said the number includes at least 40,000 hardcore fighters but rises to more than 200,000 members counting part-time fighters and volunteers who provide rebels everything from intelligence and logistics to shelter.

The numbers far exceed any figure presented by the US military in Iraq, which has struggled to get a handle on the size of the resistance since toppling Saddam Hussein's regime in April 2003.

A senior US military officer declined to endorse or dismiss the spy chief's numbers.

"As for the size of the insurgency, we don't have good resolution on the size," the officer said on condition of anonymity.

Past US military assessments on the insurgency's size have been revised upwards from 5,000 to 20,000 full and part-time members, in the last half year, most recently in October.

Defense experts said it was impossible to divine the insurgency's total number, but called Shahwani's estimate a valid guess, with as much credence, if not more, than any US numbers.

"I believe General Shahwani's estimation, given that he is referring predominantly to active sympathizers and supporters and to part-time as well as full-time active insurgents, may not be completely out of the ballpark," said defense analyst Bruce Hoffman who served as an advisor to the US occupation in Iraq and now works for US-based think-tank RAND Corporation.

Compared to the coalition's figure, he said: "General Shahwani's - however possibly high it may be, might well give a more accurate picture of the situation."

Anthony Cordesman, an Iraq analyst with the Washington-based Center for Strategic and International Studies, put Shahwani's estimates on an equal footing with the American's.

"The Iraqi figures do... recognize the reality that the insurgency in Iraq has broad support in Sunni areas while the US figures downplay this to the point of denial."

Shahwani said the resistance enjoys wide backing in the provinces of Baghdad, Babel, Salahuddin, Diyala, Nineveh and Tamim, homes to Sunni Arabs who fear they will lose influence after the elections.

Insurgents have gained strength through Iraq's tight-knit tribal bonds and links to the old 400,000-strong Iraqi army, dissolved by the US occupation in May 2003 two months after the US-led invasion, he said.

"People are fed up after two years, without improvement. People are fed up with no security, no electricity, people feel they have to do something. The army was hundreds of thousands. You'd expect some veterans would join with their relatives, each one has sons and brothers."

The rebels have turned city neighborhoods and small towns around central Iraq into virtual no-go zones despite successful US military efforts to reclaim former enclaves like Samarra and Fallujah, he said.

"What are you going to call the situation here (in Baghdad) when 20 to 30 men can move around with weapons and no one can get them in Adhamiyah, Dura and Ghazaliya," he said, naming neighborhoods in the capital.

The spy chief also questioned the success of the November campaign to retake Fallujah, which US forces have hailed as a major victory against the resistance.

"What we have now is an empty city almost destroyed... and most of the insurgents are free. They have gone either to Mosul or to Baghdad or other areas."

Shahwani pointed to a resurgent Baath party as the key to the insurgency's might. The Baath has split into three factions, with the deadliest being the branch still paying allegiance to jailed dictator Saddam Hussein, he said.

Shahwani said the core Baath fighting strength was more than 20,000.

Operating out of Syria, Saddam's half-brother Sabawi Ibrahim al-Hassan and former aide Mohamed Yunis al-Ahmed are providing funding and tapping their connections to old army divisions, particularly in Mosul, Samarra, Baquba, Kirkuk and Tikrit.

Saddam's henchman, Izzat Ibrahim al-Duri, still on the lam in Iraq, is also involved, he said.

Another two factions, which have broken from Saddam, are also around, but have yet to mount any attacks. The Baath are complemented by Islamist factions ranging from Abu Musab al-Zarqawi's al-Qaeda affiliate to Ansar al-Sunna and Ansar al-Islam.

Asked if the insurgents were winning, Shahwani answered: "I would say they aren't losing."