A Victorian woman waited for an ambulance for four hours on Tuesday with head injuries and had to call triple zero two times before an ambulance was dispatched, the state opposition claims.
Premier Denis Napthine was yesterday confronted in Parliament with the Sebastopol incident, with Parliament House's public gallery filled with ambulance paramedics.
Opposition leader Daniel Andrews said Mr Napthine made no attempt to address this issue when asked.
"This woman not only waited for over four hours, she rang 000 two times before an ambulance was dispatched," he said.
"This is simply not good enough and the Premier arrogantly shirks the issue and showed contempt for the paramedics that came to hear what he had to say."
The Premier has agreed to investigate the issue.
"Only because Labor raised this issue did the Premier reluctantly agree to investigate the issues from last Friday."
Labor's health spokesman Wade Noonan said ambulance response times were going backwards.
"Ambulances are taking longer to arrive at emergencies, they are spending longer ramped up outside hospitals, and they are increasingly unable to transfer their patients into crammed emergency departments."
Ambulance Victoria is being sought for comment.