The Sketch: Up the staircase and down the ladder? Blair can't win it

Tony Blair can't win his student finance vote. The rebels have mobilised.

There are more than 160 signatories to the Early Day Motion denouncing it, more dissidents are in the wings, and only 81 antis are needed to defeat the motion. I predict a government majority of two.

The minister, Charles Clarke, declares that he will not "pull up the ladder of opportunity" but will instead "lower the barriers to access" and in case that's not enough will also "build a staircase of opportunity". He's a handy man to have around.

But do we need a staircase as well as a ladder of opportunity? And why can't we have an elevator of opportunity as well? Unintended consequences are difficult, perhaps by definition, to predict.

But Tony Blair's top-up proposals will probably mean fewer students at university, far fewer working-class students, fees rising to £10,000 a year in due course, and an Access Regulator protruding like a vile wart from the body politic.

And - not that I've got a degree in economics - if the supply of graduates increases won't the price of them fall? And won't that discourage people from going to university after all?

Tim Yeo told the House that the proposal would certainly create two tiers of students - those willing to incur £30,000 of debt and those who weren't. We can't be too admiring of Mr Yeo, alas, as he's in one of his cyclical downturns and far from learning his lines he can hardly summon the energy to read them out.

Peter Luff made a good point about a newly qualified, newly married couple of teachers who'd start their careers with £50,000 of debt. Mr Clarke said teachers were specifically provided for. Would doctors also be specifically provided for? Or would they be starting their married lives with £200,000 of debt between them?

Fees would never go up to American levels, Mr Clarke promised; he would tell vice-chancellors: "You're not on. It won't happen." It's Burke, isn't it? Nearly?

But the most damaging shots, as is so often the case, were fired by the minister's own side. Nick Brown asked why the Government was "philosophically attracted to a market-based solution?"

The minister whiffled and waffled. It was nothing to do with dogma or obsession or even philosophy, it was just a system of prices that encouraged students to make informed choices between different priorities. What we know as a market.

Joan Humble put the practical question: how will universities be able to charge for cross-course modules? When the philosopher wants to do some ornamental medieval history, how can that be priced? There may be an answer to this, but it eluded the minister.

Denis Skinner made a grave contribution, slow and rather sad. It suits him. He should do it more often. Perhaps he will as time goes on. He concluded "the Government has bitten off more than it can chew". That may be true. Maybe they'll just gulp it down.