Susan Pember, the Government's further education supremo, said some colleges are lagging behind in the drive to extract more cash from students.
Speaking at a conference on the future of adult education this week, the FE director at the Department for Education and Skills said her colleagues will not be diverted from priority areas, including adult basic skills, those who are trying for a level 2 qualification and increasing the number of 16-year-olds who stay in education.
She said the Government was committed to learning "for its own sake" but insisted there should be honesty about which areas were to be given priority.
Delegates at the conference, held in London by the National Institute of Adult Continuing Education on Tuesday, were told there is a "formidable agenda" for adult learning.
Ms Pember said: "We have made it clear that by the end of the decade we want the national fee assumption to rise to at least 50 per cent for some activities and there is no reason that some adult activity could not be full cost and compete with private-sector activity.
"I know there is a genuine desire not to price learners - particularly those who are less well-off - out of the market. No one wants that. So we need to find a way of safeguarding college income without pricing out any learner.
"I know that many providers are yet to be persuaded of the strong stance that the Government has taken on fees. But when we see some providers - and not just those in affluent areas - doing pretty well at collecting fee income, and others making no charges at all, we surely should take a closer look at that," said Ms Pember.
The Association of Colleges has said its members need more time to raise fees, although it is not opposed in principal to students making a greater contribution.
The Government's call for higher fees applied particularly to so-called "other learning" - which falls outside its priorities of increasing vocational skills and employability.
Niace and the AoC have argued that much of this "other learning" actually contributes to government priorities by offering a taste of education which leads adults into more vocational subjects or basic skills training later on.
While the debate continues on adult education fees, colleges have been complaining that some of the mainstream work, which is supposedly funded entirely by the Government, is leaving them out of pocket.
Research by the Learning and Skills Development agency showed colleges are an estimated pound;100 million-a-year out-of-pocket as a result of the influx of 14 to 16-year-olds studying part-time in FE.
There have also been claims that funding has not matched the Government's pledge to guarantee places for 16 to 18-year-olds, with colleges having to raid other budgets to cover the cost.