The Shadow Health Minister Darren Millar described the figures about ambulance response times in 2012 as "shocking" and "inexcusable".
He said "we have a big problem in the way that our emergency care system is operating in Wales", both in terms of ambulances and A&E departments.
The Welsh Government has commissioned a review into how emergency response times can be improved, which will report next month.
More top news
Met office Yellow 'Be Aware' Warning of strong winds
After a dry end to the day, there'll be a few showers this evening Winds getting stronger overnight.
If you missed tonight's episode of Wales This Week, Test Tube Triumph, you can now catch up here