STUDENTS at Huddersfield University mounted a protest after a candidate in the union's presidential election was banned from taking part because he is not full-time.
Ray Cooper, 41, a mature student who is studying for a masters degree in information computing systems, has been a student at the university for seven years.
He worked as commercial manager for Huddersfield University Student Union for 13 years and believed his experience would make him an ideal candidate for president.
His name was accepted and he went on a training course for the role.
But on the day that the election campaign was due to start, Mr Cooper was told by the Union's deputy returning officer that he was not eligible.
Mr Cooper, of Manor Park, Mirfield, said: "I was told that part-time students can not stand for president because they are banned by the constitution.
"I could understand it if they were concerned about distance learning, such as Chinese students studying over the internet.
"But I am here at least eight hours every week, which is the same as some students on full-time courses."
Mr Cooper, who is married with two children aged 11 and six, said 7,368 students were part-time at Huddersfield University - so 45% were effectively discriminated against.
Mr Cooper had been prepared to take the matter to Huddersfield County Court and seek an injunction preventing the election taking place.
But he cancelled the court hearing after the remaining candidates agreed to take up the fight for part-time students.
Mr Richard Hartley-Parkinson, 22, editor of the Huddersfield Student newspaper, picketed outside the Student Union building with friends today.
He said: "I think its an important issue.
"I am concerned that the student union is allowed to discriminate against about 45% of the people it is supposed to be serving."
Mrs Jenny Haigh, deputy returning officer at Huddersfield University Student Union, said: "The constitution, whether it is right or not, is no different to any other law.
"If it is found to be discriminatory it has to be challenged.
"But it has to be done constitutionally because otherwise it makes a mockery of the constitution."