Pembrokeshire's school pupils have on average £229 less spent on their education each year than their English counterparts, new figures reveal.
Preseli Pembrokeshire AM and Shadow Education Minister Paul Davies says that children in Wales are missing out because of the spending gap.
In England the average spend per pupil is £5,956, but in Pembrokeshire the figure is £5,727.
"The gap in spending per pupil between Wales and England is unacceptably high – and getting wider," said Mr Davies.
"Unless we close it children in Wales will continue to be denied the same sort of learning opportunities enjoyed by pupils across the border.
"That's why the Conservatives are proposing piloting a system of 'free schools' in Wales where funding is channelled direct to schools, allowing them to make spending decisions based on local priorities. "