There is nervousness about a proposal for teachers to take classes across primary and secondary schools.

The Government is looking at changing how teachers are trained, and is considering having them ready to teach across the curriculum.

Post Primary Teachers Association president Jack Boyle told Mike Hosking there should be a warning against assuming that teachers with general skills can slot in and teach maths or other specialist subjects anywhere in New Zealand schools.

"The most important thing that we need to understand is you cannot undermine the fundamental importance of subject-specific expertise," he said.

LISTEN ABOVE AS JACK BOYLE SPEAKS WITH MIKE HOSKING