It was "very hard" for Iraq to declare weapons programmes that did not exist, former United Nations chief weapons inspector Hans Blix has told the inquiry into the Iraq war.

Dr Blix said UN Security Council resolution 1441, passed four months before the March 2003 invasion, gave Saddam Hussein the "chance for a new start".

He told the Iraq Inquiry he privately believed Saddam had kept weapons of mass destruction, but criticised the short time his Unmovic inspection team was given to search for them.

Dr Blix said he was in favour of resolution 1441, passed on November 8, 2002, which declared Iraq in "material breach" of its obligations to disarm and paved the way for the return of weapons inspectors.

"The declaration, I felt, might give Iraq a chance for a new start," he said.

The former weapons inspector said he believed another resolution explicitly authorising military action was needed before attacks could be launched on Iraq.