Alan Howarth, who crossed the floor of the Commons to join Labour this week, is the second ex-further and higher education minister to say his disillusionment with Conservative politics was linked to his period in the post.
He follows George Walden, who announced his decision not to stand again for Parliament earlier this summer, citing among other things a dislike of "the things one has to do as a minister" and accusing the Government of ducking the important education issues.
Mr Howarth said this week: "By 1992 I had become very unhappy with the squeeze on the unit of resource in higher education. We were right to go for the early phase of rapid expansion. It was appropriate because it was quite possible for the institutions of higher education to find economies.
"In my later period of office, however, it became clear to me that we were going beyond the point at which our quest for economies could provide greater efficiency. In fact, through squeezing the unit of resource, the quality of studies was very much at risk."
Since leaving the Government he has been a persistent critic, rebelling over the Jobseekers Bill, which he said "sought to rehabilitate stigma from its decline at the hands of political correctness", and protesting at the funding squeeze on local education authorities.
His move is one few would have predicted when he entered the Government in 1989. He was regarded as a right-wing protege of self-proclaimed "unashamed reactionary" Rhodes Boyson.