Time flies. It’s thirty years since, as a first year student, I listened to a debate in the Public Lecture Theatre on Melbourne University’s membership of the Australian Union of Students — paying particular attention, as did everyone, to the lead speaker in favour of seceding from AUS, a charismatic centre-unity activist from Monash named Peter Costello.

So it struck a chord yesterday when finance minister Lindsay Tanner said of Costello (see Hansard, page 56) “I have known him for a very long time, longer than most of you characters have known him, and I cannot work him out.”

Costello had chosen to end a long parliamentary silence by speaking on the Higher Education Legislation Amendment (Student Services and Amenities, and Other Measures) Bill — the government’s legislation to repeal voluntary student unionism (VSU). It was a good speech (same Hansard, pages 9-12) too, even if some of it was an exercise in nostalgia. Like many politicians, Costello evidently enjoys refighting the battles of his university days.

He acknowledged that in the AUS era he had supported compulsory student unionism himself, and although he glossed over the extent of that (and the extent to which he was associated with the ALP), his reasons for abandoning it seemed convincing. But there was no explanation of how that became a national political issue: why is the funding of student organisations being debated in Canberra instead of settled on campus?

Nor did Costello explain why, if levying students to fund services is wrong, it would be okay to fund the same services out of taxation revenue.

Back in 2005, debating the original VSU legislation, Mitch Fifield more sensibly remarked that “If it’s wrong to compel students to pay a fee, then I think it’s wrong to slug the taxpayer for that money.”

But most glaringly, there was no explanation of why Costello chose this issue for a set-piece speech in parliament. Is it just that his student experience gives him particular expertise? Or is it a further sign of his positioning for an eventual leadership challenge, and an indication of where he is looking to for support?

Ten years ago, Costello was the great hope of the Liberal Party’s left.

But that alliance is now looking decidedly threadbare and yesterday’s speech will not have helped to repair it. For the left, VSU is at best an irrelevance, but for the right it is totemic.

No doubt Costello’s sentiments on the issue are genuine, but they also reflect a shrewd calculation of where the numbers he needs are to be found.

Whether the Liberal Party’s best interests are really served by regressing to the 1980s, in ideology or anything else, is of course another question.