One year on from MPs' recommendation that prisoners should be paid the same whether working or studying, no action has been taken.
Some prisons pay inmates up to three times as much per week to perform menial tasks such as packing margarine, rather than for studying. Those on training courses earn pound;5-pound;7 a week.
Steve Taylor, director of the Forum on Prison Education, acknowledged some prisons were providing more productive work.
But he said: "The one thing that keeps coming up in every prison is pay for education compared to work. They say students in the community don't get paid: but now many of them get the education maintenance allowance."
Prisoners in education are three times less likely to reoffend. The forum estimates equalising pay would cost pound;2 million a year.
"Ten pounds a week extra for each prisoner may not sound much to us, but it's five phone- cards, or it's tobacco or shampoo or something else," he said.
Mr Taylor was speaking after the forum published an analysis of the Government's response to the House of Commons education select committee report.
It shows that more than half the recommendations have been met partly or in full, which the forum said was "good progress".
But Mr Taylor said some of the most important principles were still not accepted by the Government.
As well as resistance to equal pay for work and training, there was still no one organisation in charge of prison education, with four quangos and government departments sharing responsibility.
The Government says equalising pay would be impractical because prison governors are able to set their own pay rates.
In its response to the select committee, it said: "Unless there was an increase in funding to prisons, the increase in pay for education would need to be funded by a decrease in payments to prisoners taking part in other regime activities, which is unacceptable."