Outgoing Green MP Sue Kedgley has called for a change to the "trench warfare" nature of Parliament, saying the public finds politicians' behaviour off-putting and childish.
Ms Kedgley, who will step down at this year's election, used her valedictory speech today to question the "polarised and confrontational" business tactics of MPs.
"Much of the time it's trench warfare in here," she told Parliament.
"The aim is to do battle, to defeat the enemy on the other side, not to debate or to listen. The heavy hitters, the point scorers and the alpha males lead the charge, and hurl abuse and insults at the other side.
"Question time, which ought to be a showcase of our democracy, routinely degenerates into a pointless slanging match."
Ms Kedgley said she had once suggested setting up a cross-party group to examine how the culture could be improved.
"But this went down like a lead balloon, and nothing much has changed since then, so there's seldom constructive dialogue or thoughtful debate in this House, and much of the time no one is even listening to our debates."
The most constructive work was done away from the cameras, Ms Kedgley said.
"In Parliament far more energy is spent on spin, and on trying to win the daily media battle, than on grappling with the crises that confront us," she said.
Ms Kedgley also raised concerns about the "excessive" use of urgency, saying that by-passing proper public consultation fuelled a growing distrust of politics.
Former Green Party co-leader Jeanette Fitzsimons, along with former member Sue Bradford, were among the more than 100 supporters who turned out to hear Ms Kedgley's farewell speech.