The government have added a new argument to their case for university top-up fees.

The higher education minister has published a new study using international comparisons to make the case for top-up tuition fees.

Alan Johnson moved to justify the government's case for variable student charges of up to £3,000 per year on Friday.

Ministers have come in for heavy criticism from all sides over the proposals, with over 150 Labour backbenchers having signed a motion expressing their concerns.

But Johnson said an international comparison put plans to charge more at English universities into perspective.

His study of 13 major OECD countries' policies showed that the government's higher education proposals are "right in principle, fair in practice and successfully tried and tested" he claimed.

The paper argued that many universities in the UK are already varying fees for non-EU students and that "tuition fees are becoming the international rule rather than the exception".

Charges have not affected access to higher education from working class communities in the eight of the 13 countries already levying fees, the minister added.

The research concluded that the UK participation rate and UK spending per student is currently less than the OECD average.

And in a swipe at critics who have called for a progressive graduate tax system, it noted that similar schemes do not exist in any of the main competitor countries.

"Some of our main competitors already vary fees and vary them successfully," Johnson noted.

"If we don't take up the challenge and improve our own levels of participation we will gradually fall further and further behind.

"In the long term this would spell economic disaster.

"The pace of change is also apparent in Asia. China and India are making huge strides and taking long term strategic decisions to improve the quality of their best universities.

"We clearly cannot afford to stand apart from the international crowd."