Pupils in Wales each had pound;273 less spent on their education than their counterparts across Offa's Dyke this year, according to new figures.
The funding gap for 2005-6 worked out at pound;257,985 for the average 945-pupil secondary school in Wales - the equivalent of 13.5 newly-qualified teachers, or 8.5 experienced ones.
Primary schools missed out on an average pound;46,956, or in excess of an experienced classroom teacher and a learning support assistant.
Plaid Cymru warned of a brain drain as teachers decide to move to better-resourced schools in England. But Jane Davidson, minister for education, lifelong learning and skills, said headteachers and opposition parties were wrong to look enviously at schools across the border.
She told the Assembly that devolution had given Wales the chance to dictate its own education agenda and chart its own policy success.
Officials claimed the funding gap was much closer when cash spent in England on private schools for special educational needs pupils was taken out of the calculations. Direct investment by the Assembly government into education has increased from pound;760 million in 1999-00 to more than pound;1,500m for 2006-7.
And as TES Cymru went to press, the minister announced a new pound;16m fund for boosting the attainment of disadvantaged children most likely to leave education without qualifications.
Around a third of primaries and three in 10 secondaries, where a fifth or more of pupils are entitled to free school meals, will receive funding for projects including literacy and numeracy support, family and community liaison, and behaviour management. Most (pound;13m) of the cash is from Chancellor Gordon Brown's pound;45m extra for public services in Wales to 2008.
Peter Black, Welsh Lib Dem education spokesman, welcomed money for disadvantaged pupils but said: "There is little point giving heads cash for more literacy and numeracy lessons when they are being forced to lay off teachers and increase class sizes."
Welsh heads have long complained that their budgets lag behind those of English schools, and that a "funding fog" surrounds how money arrives from the Assembly via LEAs.
Iwan Guy, acting director of the National Association of Head Teachers Cymru, said the funding gap figure would be skewed even higher if additional grants awarded to schools in England - such as the extended schools fund and leadership incentive grant - were taken into consideration.
Brian Rowlands, secretary of the Association of School and College Leaders Cymru, said embattled Welsh heads inevitably and rightly envied English schools that received fat cheques.
Janet Ryder, Plaid Cymru's shadow education spokesperson, said the funding disparity showed the Assembly government was failing children and schools.
She said: "Staff who have previously taught in England appreciate that the curriculum and teaching is a lot better in Wales, but without the resources that they had in England it is becoming difficult to do their job."
The figures - for LEA spending per pupil in England and Wales - show that the average spend in Wales went up 4.9 per cent to pound;4,382 in the financial year 2005-6. But in England, spending went up 5.3 per cent to pound;4,655 - a gap of pound;273, or pound;129 if London is removed from England's figures.
In the previous year, the gap was pound;157 per pupil, or just pound;23 excluding London. Professor David Reynolds, from Plymouth university, said:
"Even without London weighting, pupils in England still have just over Pounds 100 more funding each this year. But it is fair to say pupils in Wales have the policy and teaching advantage."