Wales’ performance in internationally recognised reading, maths and science tests has fallen to its lowest-ever level.

Schools in Wales lag behind the rest of the UK in the latest Programme for International Student Assessment (Pisa) test results, with the gap widening since 2018.

Wales continues to be below the OECD average and has ranked bottom of the performance table for UK nations since joining Pisa in 2006.

The three-yearly Pisa tests – which involved 690,000 15-year-olds in 81 countries – are carried out by the Organisation for Economic Cooperation and Development (OECD).

Andreas Schleicher, the OECD’s director for education, said: “It’s not just that Wales is the lowest performing region in the UK but it’s also the one with the steepest decline.”

Mr Schleicher added that Wales is more comparable to a country like Malta than top performing education systems around the world.

Wales scored 466 in maths, 473 in science and 466 in reading compared with OECD averages of 476, 485 and 476 respectively.

A decline in maths scores from 487 in 2018 to 466 is equivalent to more than a year’s learning, according to the OECD.

Jeremy Miles, Wales’ education minister, said the pandemic had derailed improvement in literacy and numeracy standards.

He said: “We have already started on a path of driving up standards in reading and maths and we won’t let these results knock us off track

“Last month we launched literacy and numeracy plans to help support learning and raise standards in these key areas.

“I have also published the first national report on the performance of our children in reading and numeracy and will do this annually to track recovery.

“We supported our schools and learners through the pandemic, we will stand together and support them now.” 

The OECD found a marked drop in many countries in the 2022 tests, which were delayed by a year due to the pandemic, finding that Covid was partly but not wholly to blame.

In 2019, Welsh ministers set a target of 500 points in maths, science and reading but the ambition was abandoned due to the pandemic.

Mr Miles stressed that improvement to education takes time as he argued that long-term education reforms such as Wales’ new curriculum will make a difference.

He said: “We have taken a once-in-a-generation opportunity to revolutionise the quality of education in Wales and I’m confident we will deliver huge benefits for our young people.”

Laura Anne Jones, the Conservatives’ shadow education minister, criticised the Welsh Government for cutting the education budget in Wales.

“All governments should be giving pupils and teachers the tools to do their best and thrive,” said the South Wales East MS.

“After 25 years of Labour running Welsh schools we have a widening attainment gap, funding being spent on the pet project of more politicians and sadly once again Wales languishing at the bottom of international league tables.

“The Labour education minister needs to get a grip of his department and give our young people the start in life they deserve.”

Heledd Fychan, Plaid Cymru’s shadow minister, described the latest Pisa results as a wake-up call for the Welsh Government.

She said: “Too many young people in Wales are living in poverty, pupil absences are unacceptably high and many schools are facing a significant deficit in their budgets.

“Despite the hard work and dedication of an overstretched workforce, the attainment gap is widening, and we cannot ignore the link between poverty and today’s disappointing results.

“Every child, no matter their background, should have an equal chance of succeeding in life.”

Jane Dodds, the Lib Dem leader in Wales, highlighted progress made under her party colleague Kirsty Williams, the former education minister. 

She said: “The results in the years following showed that these reforms were bearing fruit.

“From 2015 and up to 2018, figures across maths, science and english were improving in Wales which saw the largest growth in test results amongst the home nations.

“But now we are being presented with figures that are three per cent below the international average.”

Mr Miles will give a statement in the Senedd about Wales’ Pisa results at about 3.30pm on Tuesday, 5 December.