Mature students are mounting a legal challenge to the government policy of targeting the under-30s for university expansion.
The Mature Students' Union confirmed this week that it had instructed lawyers in an attempt to have the government's target to get 50 per cent of all under-30s into higher education by 2010 declared illegal on the grounds of age discrimination. The union also hopes to overturn the age limit on student loans, which are not available to the over-54s.
The union's lawyer said the action had "legal merit".
MSU president Alan Colman said: "We are looking at the possibility that the government's concentration on a quota for the under-30s entering higher education (is) contrary to United Nations, European Union and UK human rights laws governing access to education, and amounts to discrimination on the basis of age, at the same time as the government issues its own age discrimination legislation."
Mr Colman said that there might also be a case against age limits on student loans. The over-50s have to make a special case to receive a student loan - convincing an interviewer that they would be employable after graduation - and no student is eligible for a loan under any circumstances once they reach 54.
According to the Higher Education Statistics Agency, 28 per cent of the UK's 500,000 undergraduates in 2001-02 were aged 31 or over. Almost 60 per cent were considered "mature", aged 21 or over.
Mr Colman said that education lawyer Jaswinder Gill of Gill's solicitors, behind many successful legal challenges on behalf of students, had been instructed to take the case forward.
Mr Gill said: "Broadly I share (MSU's) concerns. If the government pushes on with its reforms, it could face a legal challenge by judicial review, arguing that the changes are unreasonable and/or irrational. If successful, this would open the floodgates for other claims. This is merely a preliminary view and I shall be seeking pro bono advice from a QC when advising the MSU."
But Garry Attle, a partner at education lawyers Mills and Reeve, said it was unlikely such a challenge "would have legs".
"There is provision in the European Convention of Human Rights that prohibits all sorts of discrimination and does enshrine a right not to be denied an education," he said.
"But it would be a fairly bold move to challenge the government's plans on this basis. All signatories of the European convention are allowed a 'margin of appreciation', which gives (them) a degree of flexibility. The 50 per cent target may fall within that margin, allowing countries to get on with things," he added.
Mr Attle said that while there was domestic legislation against race, sex and disability discrimination, there was no legislation outlawing age discrimination. Government moves to rectify this were focused on employment, not education, he said.
"There was a recent case where a mature student sought a judicial review when he was turned down for a medical course on the basis of his age, but the courts allow discretion to universities to make their own decisions," he said.
A spokeswoman for the Department for Education and Skills said: "Our aim is to increase opportunities for students of all ages. No student will have to pay fees up front and every graduate will repay according to personal circumstances. That is a fair deal no matter how old you are."