Media playback is unsupported on your device Media caption Dr Philip Dixon said there was no shame in seeking help

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

Dr Philip Dixon pointed out head teachers, schools and councils have been taken to task over the last 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.

Pisa assesses pupils' skills in maths, reading and science every three years and more than 70 countries were signed up to take part in the 2015 test.

The results are expected in December but in the last Pisa tests in 2012, Wales performed worse than the rest of the UK.

"We need some outside help," the former ATL Cymru director told BBC Wales' Sunday Politics Wales.

"I don't think there's anything wrong in saying 'we can't solve this on our own, we need to get some international world-leading help'."

He added: "As you would with a local authority, you set up a recovery board. So you get those who have got a track record in the other jurisdictions of the United Kingdom; from Northern Ireland, Scotland and, dare I say, England who can turn government departments around.

"You've got some world leading experts then as well and you've got some experts from Wales. But they wouldn't be the dominant ones. And they would be focused on delivery - how do you actually get these policies delivered on the ground?"

The Welsh Government said regardless of the Pisa results, it would "remain absolutely focussed" on following the "best international evidence in order to continue to drive up standards in our schools".

A spokesman added: "It is not good enough to limit our ambitions to simply looking across the border, we must strive to be up there with the best in the world.

"That's why the education secretary recently commissioned the highly respected Organisation for Economic Co-operation and Development (OECD) to provide support and challenge to the Welsh Government's work on education reforms to make sure they are on track."