With an election looming as soon as May, Blair faced an audience of disenchanted women who voted Labour in 2001 - but might not in the future.
Blair was repeatedly challenged over the Iraq war and was asked by one audience member to apologise for the conflict in order to regain public trust.
One woman told Blair: "Will you have the humility to tell us you actually made a mistake, because if you did I would vote for you again?"
Blair responded: "I'm very sorry, if you want me to say I regret the decision to go to conflict, I can't do that for you".
"All I can do is tell you it was the toughest decision I ever had to take ... I still believe it to be right."
Blair also insisted he had not misrepresented intelligence on Saddam Hussein's non-existent weapons of mass destruction.
"I have apologised for the intelligence being flawed although I honestly represented the intelligence to people that we had at the time," he said.
Other women did not mince their words on the programme, broadcast on the ITV network.
"You have lost my respect," one said, while another stated: "You're constantly failing to meet the criteria you set yourself in 1997" after Labour's first election win.
Blair said he still believed his
decision to go to war was right
The female electorate is considered crucial in the run-up to elections, as historically women change their party allegiance more easily than men.
An opinion poll published on Sunday suggested that female voters are turning increasingly against Blair.
According to the survey conducted for the News of the World newspaper, only 9% of female voters want Blair to carry out his stated intention of serving a third consecutive term in office.