The current system’s regressive - those who earn the most pay the least, because they’re not subject to interest over 30 years - they pay it off over the first few years of work in its entirety.
Cable’s proposal (it had to be him as it was in his portfolio) was a slightly changed form of the findings of the Browne report on higher education funding - it was a given that it was going to be put forward in 2010 as both the Tories and Labour were going to go ahead with those, but importantly the Lib Dems negotiated a clause in the coaltion agreement that meant they didn’t have to vote in favour of it.
Obviously Cable was put in a position where he couldn’t do much else (it would be ludicrous if he voted against his own bill), but the coalition allowed every other Lib Dem to abstain. Instead, Clegg chose to do the media rounds as the biggest advocate of a regressive and financially illiterate scheme - (lest we forget there’s a black hole looming as too few loans are expected to be paid off to actually pay for those that are expected to be written off). It’d have still gone ahead if Clegg could have kept the troops in line (almost as many Lib Dems vote against as voted for), but the damage in trust wouldn’t have been anywhere near as fierce.
I’ll say it again. All he had to do was get his party to abstain and say the Lib Dems didn’t like the plan but they’d done their best to improve it within the bounds they could and under the negotiated terms of the coalition agreement they would regretfully not vote against the increase as they previously pledged.