I write as a member of an endangered species, I fear.

I was lucky enough to be educated at Oxford University, have been a teacher for nearly 40 years and have also nearly paid off my mortgage.

Why does that make me endangered? Because, if the vast hike in tuition fees for students goes ahead, someone with my qualifications would leave university with a combined debt for tuition and maintenance of upwards of £60,000.

Entering the teaching profession, or any of those areas in which a good degree is needed, just would not provide the remuneration to repay a loan of that nature nor would someone with that debt be attractive to mortgage providers.

I certainly would not have chosen to go to university if that prospect had faced me.

Much now depends on how the Liberal Democrats will vote: the signs are not good.

Mr Clegg and Mr Cable have suddenly found reasons to be unable to come to speak in Oxford. In a display of cynicism which shows just how quickly he has grown into the habits of high office, Mr Cable has tried to draw a distinction between a pledge to resist the raising of fees and a firm promise to do so.

Well, if I pledge that I will take my class on an outing, they regard that as a promise!

Many students voted Liberal Democrat because of the pledge, which their candidates all signed. If the MPs for whom they voted fail to vote against the raising of fees, they will punish them at the next election.

Mere abstention will not do here: there are too many interested parties watching.

I was at Oxford throughout the angry years of student protest and never attended a demo or sit-in. But now I can only commend any legal and peaceful form of demonstration against these measures.

The Liberal Democrats might do well to ponder on these words of Euripides, spoken by a character who comes to no good end: “My tongue swore, but my mind was still unpledged.”

Martin Roberts, Stone Close, Botley