'Outside help' needed to change education in Wales

External experts are needed to improve how changes in education are implemented, the former head of one of Wales' largest teaching unions has said.

The former ATL Cymru director Dr Philip Dixon pointed out head teachers, schools and councils have been taken to task over the past 10 years in a drive to improve standards.

But he said the focus should be on the Welsh Government's education department if the latest Pisa results are poor.

The Welsh Government said it was too early to speculate over Pisa.