WALES is still the worst performing UK nation for maths, science and reading, according to an international league table released today.

Every three years the Programme for International Student Assessment (PISA) surveys around half a million students from across 65 countries which are part of the Organisation for Economic Co-operation and Development (OECD).

Can you do the PISA test? Try it here by clicking the link at the foot of the page.

The last series of tests, which took place in 2009 and were wholly separate from standard exams such as GCSEs, focused on reading and ranked the UK 25th behind Denmark, France, Ireland, Germany, Liechtenstein, Estonia, Poland and Korea.

In 2009 Wales rated the lowest of the UK nations in reading, maths and science.

Three years on, with the emphasis on maths, Welsh PISA test results for maths and science in 2012 were worse than 2009, but reading had improved slightly.

England had improved in all three categories, while Scotland improved in both maths and reading but dipped in science, and Northern Ireland also performed worse in all three categories.

The UK average has either remained the same or improved in maths, reading and science, but the UK is now ranked 26th among OECD countries in the 2012 performance table.

Speaking at a meeting of the Institute of Welsh Affairs Gwent branch in Cross Keys last week, the director of school standards in Welsh Government, Dr Brett Pugh said of the Welsh education system: “I agree, it’s a system that’s not performing as well as it should.”

Yesterday the Conservative shadow minister for education Angela Burns AM claimed the results would determine whether Labour is on course to meet its 2015 target of Wales being in the top 20 of all OECD nations.

Robert Lloyd Griffiths, director of the Institute of Directors (IOD) in Wales described the results as “bitterly disappointing” and blamed historic complacency in the UK.

Education and Skills Minister Huw Lewis said the results were "disappointing" and showed Wales still "got a way to go before we close the gap with the OECD’s best performing countries".

He added: "There are signs of some progress in reading, but significant improvement was never likely at this stage.

"Everybody working in and around the Welsh Education sector needs to take a long hard look in the mirror this week. The PISA results are stark and the message is very clear, we must improve educational attainment and standards right across the board.

"I am confident that the measures we’ve put in place since the last set of PISA results are the right way forward for Wales and we won’t be distracted from delivering them. Today’s news simply reinforces our case for the ambitious reforms we have already developed and everyone across the education sector in Wales now needs to play their part."