Labour has been an utter catastrophe for education. But Cameron has got it wrong by suggesting teachers should only be chosen from an academic elite.
Academic ability, beyond that required to deliver the syllabus has no correlation with the ability to teach.
Many of the finest teachers in the 50's and 60's had no degree at all, but had charisma and enthusiasm. Many of the worst teachers today have excellent qualifications but little enthusiasm or life experience.
Increasing the requirements to teach will simply narrow the pool of available talent down further. The net result will be more and more kids being taught by untrained teaching assistants.
Academic ability and the ability to teach are not the same thing.