AAP - ACCUSATIONS OF misguided patriotism and overt chest-beating have been fired in NSW parliament as MPs traded barbs over Kokoda.

Question Time turned ugly Wednesday when Premier Kristina Keneally mocked Opposition Leader Barry O'Farrell, who was asked by a radio station earlier in the week what made him a strong opposition leader.

Mr O'Farrell replied by pointing to the fact that he walked the Kokoda Track in 2008.

"Well so did Miss Australia, so congratulations Barry," Ms Keneally told journalists.

"The leader of the opposition has been out there telling people how strong he is, how tough he is," she said, "and what is he using as his example? He is using one of our most sacred institutions - the Kokoda Trail."

The chamber erupted as Mr O'Farrell delivered a scathing response.

"You raised the attack on Kokoda," he told the premier, who moved from the US to Sydney in 1994. "I understand you don't understand our history - some of us do."

MP Charlie Lynn, who has walked the Track 59 times in the past 19 years, later told reporters that Mr O'Farrell hallucinated and needed to lie down when they were ascending Imita Ridge.

"Barry is a big unit - he put in a lot of work to get fit enough for Kokoda - he did it really tough," Mr Lynn said.

“Kokoda is about the ability of the human spirit to conquer adversity and Barry proved that. I've said for years that you don't understand Kokoda until you've trekked Kokoda.

Mr Lynn suffered the loss of 80 percent vision in his right eye and 10 percent vision in his left eye after contracting an infection on his most recent trek.

He has been undergoing treatment to hopefully improve his vision.”