'No quick fixes' to turn around education in Wales says Huw Lewis
There are "no quick fixes" for turning the education system around in Wales, the education minister has admitted.
Huw Lewis warned it would take "some years" to learn lessons after Wales again fell behind the rest of the UK in an international study.
The UK government's Education Secretary Michael Gove described Wales as a "country going backwards".
Wales had lower results on average in the three subjects than England, Northern Ireland and Scotland.
Facing questions from assembly members, First Minister Carwyn Jones assured them education in Wales was not in "crisis".
The figures, from the Programme For International Student Assessment (Pisa) tests, were published by the Organisation for Economic Co-operation and Development (OECD).
Mr Lewis said Wales was on an "education improvement journey" which had "no quick fixes" within it.
He told BBC Wales: "It's going to take some years to learn the lessons of Pisa and turn the system around to meet the challenges it meets to us.
"Everyone from myself to leaders of local authorities, teachers, school governors - everyone needs to take a good long look in the mirror and recognise the challenge is for them as well as the people around them."
Mr Lewis admitted: "There could be questions about us taking our eye off the ball in the mid 2000s around the basics in education."
But he insisted Welsh ministers did "take heed" of previous poor Pisa results in 2009, and instituted "one of the most radical and ambitious reform programmes that Welsh education has ever seen".
But he said such reforms "take time to have traction".
"It's barely a year since these reforms were instituted," he said.
'Off the ball'
But he conceded significant mistakes might previously have been made in key areas.
"I think there could be questions raised around taking our eye off the ball in the mid-2000s around the basics in education, literacy and numeracy - we've certainly put that right".
"We're going to go for the very best we can achieve... everyone in the system, I'm asking them to join with me in recognising that to do that we need to step change in terms of what we expect from the system and the challenge we put down to our teachers, our pupils and to the machinery of education in Wales.
"We need to take things to a whole new level," he added.
While Mr Lewis said there was "not all that much to celebrate" in the rest of the UK, Mr Gove used Wales' performance in the Pisa tests to berate the Labour front bench in the House of Commons.
He told MPs: "I'm afraid it's the case that in Wales, a country for which I have an enormous amount of affection, the Welsh Labour government chose to abandon league tables, abandon external accountability, and the current Welsh administration is unfortunately not matching our commitment to spending in schools.
"And the conclusion that we can draw from this is, if you want to know what our education system would be like if the country were foolishly to vote Labour at the next election, you need only to look over the Severn to see a country going backwards."
During tense exchanges on education in First Minister's Questions in the Senedd, Welsh Conservative leader Andrew RT Davies said the Pisa results were "more damning evidence of educational failure under Labour".
He told Mr Jones: "You cannot show any humility to the people of Wales, who've depended on education as a route out from poverty, as a route to good jobs, and above all developing an economy fit for the twenty-first century."
Plaid Cymru leader Leanne Wood said the Welsh government would be in "special measures" if it were a local authority.
"Why should parents continue to trust your government with their children's education?" she asked.
For Liberal Democrat leader Kirsty Williams the "abject failure" of Labour's education policies had been "exposed for everyone to see".
"As a Labour assembly member for 14 years, as a cabinet member for 13 years and now as the first minister of our nation, are you not ashamed?" she said.
Mr Jones insisted there had been "an improvement" but "not enough" this year, and he listed ways he argued ministers were seeking to improve educational performance:
"The National Literacy and Numeracy Programme, the National Support Programme, supporting professional development, Teach First Wales, leadership development, strengthening accountability, Learning Wales, the national model for regional working and dealing with attendance and behaviour, all put in place since 2009," he told AMs.
"As I've said, it will take a little more time for these improvements to have their full force."
The first minister said his message to all three opposition parties was "if you don't like it, what would you change?"
The opposition parties had "signally failed" to outline what they would do differently, he said.