Michael Gove's education shake-up received a Commons pasting yesterday after a global study exposed Britain's underperformance on the world stage.

The latest Programme for International Student Assessment (Pisa) study showed Britain continuing to stagnate, lying 26th out of 65 countries for maths, 23rd for reading and 21st for science.

In the 2009 edition of the OECD study of 15-year-olds Britain ranked 28th, 25th and 17th.

Education Secretary Mr Gove said the study, which showed Singapore, South Korea and Japan topping the charts, backed him up.

He claimed his policies were driven by those countries' emphasis on autonomy for head teachers and "rigorous" accountability.

But opposite number Tristram Hunt said the leading countries require highly qualified teachers.

Meanwhile "under your deregulation agenda the South Leeds Academy can advertise for an unqualified maths teacher with just four GCSEs," he told Mr Gove.

"We have seen a 141 per cent increase in unqualified teachers in free schools and academies under this government."

Meanwhile Sweden - held up as a model by Mr Gove - has nosedived thanks to unqualified teachers and unregulated free schools.

"The lesson from Pisa is clear - that you have freedom with accountability, autonomy with minimum standards or else you'll end up with the chaos of your al-Madinah school," said Mr Hunt, referring to the mess at the Derby free school.

TUC leader Frances O'Grady blamed Britain's underperformance on a succession of "pointless shake-ups."

"Nothing typifies this better than Mr Gove's enthusiasm for increasingly bizarre free schools."

ATL union leader Mary Bousted said Pisa had pointed to poverty as a major barrier to learning.

"Schools cannot fully compensate for this coalition government's policies, which have led to increasing numbers of children living in poverty and coming to school without having eaten or slept somewhere safe."

Meanwhile the results showed that Wales had fallen significantly behind the rest of Britain.

It scored an average of 480 points across the three tests, compared with England's 503 and Scotland's 506.

Teachers' union NASUWT leader Chris Keates warned against repeating the "Pisa panic" which followed Wales's poor results in 2009.

"It led to some poorly thought-through lurches in policy," she said.