Heads and teachers in Wales are in "denial" about the country's poor performance in international tests and the need for urgent improvement, according to the chief inspector of schools.
Ann Keane, head of Estyn, told TES Cymru that a minority of staff are not taking the results of the Programme for International Student Assessment (Pisa) tests seriously enough.
In the 2009 Pisa programme, run by the Organisation for Economic Co- operation and Development, Welsh 15-year-olds performed worse in all subjects than in the previous programme and fell further behind those in the rest of the UK.
Ms Keane, who recently entered her second year as chief inspector, said: "I don't think there's universal acceptance that Pisa is giving us a real wake-up call.
"A minority of people are not taking Pisa seriously and deny we need to make significant improvements. People have got to step outside their denial. I think that if we get the commitment from heads, teachers and local authorities to improving skill levels generally, we will get better Pisa outcomes."
Education minister Leighton Andrews has announced a series of tough reforms with the aim of making Wales one of the top 20 school systems in the 2015 Pisa tests.
Assessments of maths, reading and science skills will be integrated into school assessments of 15-year-olds. Secondary schools will be expected to work on skills with their Years 8 and 9 students, who will face the next round of Pisa tests.
Ms Keane said there was no reason why the minister's goal could not be achieved, and argued that it was right to include the Pisa tests in the curriculum.
"Pisa goes to the core of what a good education is," she said. "Education is about teaching children how to think, evaluate, recognise what is important, make judgments, communicate and present.
"Pisa tests all that and you can't get through a Pisa test having learnt by rote. Pupils in Wales probably weren't used to sitting that kind of test. For many, it was a novel experience."
But Rex Phillips, Wales organiser of the NASUWT teaching union, accused educationalists like Ms Keane of being "preoccupied" with Pisa.
"It would be a phenomenal error of judgment to reorganise the education system around international studies like Pisa," he said.
"Ann Keane's statement is fairly crass and she should remember that education for education's sake should be a goal in itself."
Estyn is working on a remit report on the delivery of the non-statutory skills framework, and Ms Keane is concerned that schools lack confidence in delivering skills.
Last week a leading academic branded skills levels in Wales "appalling". John Ball, of Swansea University's school of business and economics, told the Westminster Parliament's Welsh Affairs committee that the country's education system "leaves a great deal to be desired".
"The skills are simply not there for inward investors," he said. "I don't think we are frankly pushing the schools the way we should be pushing them."