Earlier this year Jane Davidson, the education and lifelong learning minister, was ambushed in the Welsh Assembly by the combined opposition parties intent on making a political point - ostensibly about top-up fees for students.

Reaching out to a wider audience more concerned with the substance of the Assembly’s education policies than with party politics, she was able to call on “evidence-informed policy” in her defence.

Such policy, too often a slogan with little substance, has become a reality in the Assembly’s formative years. Groups of people without political or organisational allegiance to the Assembly have been asked to review the available evidence and come up with policy recommendations for the minister to consider.

Professor Teresa Rees, the Cardiff academic who chaired the review of financial support for students, has twice in the past three years spent many months gathering evidence to inform difficult political choices. The review that I chaired of assessment policies at key stages 2 and 3 was another example of the development of policy options being entrusted to a group with links to, but not part of, the Assembly’s own policy development processes.

But can this approach to evidence-informed policy in Welsh education be sustained? Governments in both England and Scotland are investing in the infrastructure to support research in education.

In Wales, the political stance appears to be to assume that the academic research, and the researchers engaged in it, will be there, should the Assembly wish to call upon it or them. That will not be possible if the capacity of Welsh higher education institutions to engage in education research continues its recent decline.

The speeding up of that decline is a by-product of the bizarre world of the UK’s research assessment exercise (RAE). Academic departments producing research of national excellence in more than two-thirds of their research output, with some elements of international excellence, have had their core funding for research withdrawn.

Without such funding, the three schools of education in Wales graded at that “3A” level in the 2001 RAE (Aberystwyth, Bangor, Swansea) are unwilling to maintain what was already a fragile commitment to education research. Those schools have been major contributors to research that is about Wales, as well as being based here.

To take the Aberystwyth example, only three of the 15 staff whose work was judged as of mainly national or international quality in 2001 are still in post four years later. In contrast Cardiff, one of two UK universities with a 5* grading in education, has been able to maintain the staffing and support systems necessary to continue to engage in education research.

Much of that work will not focus on Wales but, in terms of research capacity, Wales now has only one HEI that is fully funded to engage in education research.

Of course academic research is not the only, or necessarily the best, source of the evidence that is needed to inform policy. And of course such research need not necessarily be based in university schools of education in Wales.

A sceptic might suggest that education academics indulging in their own esoteric research interests have little to offer to the current ferment of policy development in Wales. And it is certainly true that much of the evidence reviewed by the group that I chaired came from other sources, such as surveys carried out by ACCAC and Estyn.

But it is also true that when the Assembly government has needed to call in academic expertise it has usually turned, not surprisingly, to academics based in schools of education in Wales (or, in Professor Rees’s case, the Cardiff school of social sciences, which embraces the study of education).

And it is research in those schools of education, never strong in UK or international terms, that is being eroded as a consequence of a changed funding regime in higher education.

What can be done? Cardiff, as the only remaining centre of excellence in Wales for education research, must have a role in any future Welsh “institute for education research”, training future researchers in an environment where there is enough of a critical mass to enable novice researchers to develop their expertise.

But for Cardiff to be the only centre of education research in Wales would to be deny the contribution that can come from small groups of experts with specialisms not covered by Cardiff and based in other higher education institutions. It is time to grasp the nettle that, in this electronic age, geographical distance need not be an impediment to such an all-Wales infrastructure.

Richard Daugherty is emeritus professor of education at the University of Wales, Aberystwyth