But Wales still lags well behind England in the performance of teenagers who leave school with at least one GCSE, other figures for 2006 reveal.

In England, only 3.4 per cent of the cohort left compulsory education without a single GCSE, compared with 6.8 per cent in Wales. Just 26 more pupils, or 2.1 per cent of the Welsh cohort, passed a single GCSE or other recognised qualification last year compared with 2005, with Wales also “tailing” England in overall performance. Nearly 54 per cent of Welsh students passed at least five GCSE or equivalent exams at grades A*-C this summer, compared with 58.1 per cent in England.

The pass rate for five grades A*-G was also higher across the border: 89.2 per cent, compared with 86 in Wales. Heads in Wales claim greater use of vocational GNVQs in English schools - which can count for up to four GCSE grades - is responsible for the widening gap between the two countries.

But academics suggest lower per-pupil funding levels and fewer initiatives focused on boosting pass rates may also explain the gap.

Figures for local education authorities also show big variations in performance. For example, in Denbighshire, Merthyr Tydfil and Newport, nearly one in 10 school-leavers failed to get a single GCSE equivalent pass, compared with just over 2 per cent in Gwynedd, and less than 5 per cent in Flintshire, Powys, Ceredigion, Pembrokeshire, and Neath Port Talbot.

An Assembly government spokesperson said direct comparisons were not possible between England and Wales because, in addition to GCSEs, GNVQs, NVQs and GCSE short courses, the English figures also include all level 1 and 2 qualifications approved by the Qualifications and Curriculum Authority.

He added: “In Wales, the increase of 2 percentage points in the number of pupils achieving five or more GCSEs grade A*-C or equivalent this year is similar to the increase in England.

“What is most important is that our young people continue to do well in their GCSE examinations and that, as a Learning Country, we continue to improve each year.”

The Assembly government also reports a 25 per cent fall in the number of 15-year-olds leaving full-time education without a recognised qualification between 1999 and 2006. Jane Davidson, minister for education, lifelong learning and skills, said the drop was a move in the right direction.

“Achieving at least one qualification is essential to give young people the chance of a better life, a better-paid job and more security for the future.

“Education is the single most important factor in preventing offending and re-offending,” she added. “We want to be sure young people do not become disengaged from education before the age of 16, and stay in education or training after 16, by encouraging the right learning options.”

For the first time this year, the Assembly government has also published a GCSE points score, which gives pupils credit for every approved qualification they take.

Secondary school performance summaries are due for a full review next year.