Liberal Democrats delegates have been urged to mount a last push to scupper plans for university top-up fees.
Students across the UK have protested against fees
Phil Willis, the party's education spokesman, said it was vital MPs were encouraged to oppose the third reading of the Higher Education Bill when it returns to the Commons later this month.
Activists at the party's spring conference voted to scrap the policy after Mr Willis said it could mean university students being "saddled with mortgage style" debts by 2010.
"This is a bill that is bad for students, bad for universities, bad for taxpayers and bad for the future of this country," he said.
Tony Blair suffered his biggest rebellion yet in the first fees vote.
The Higher Education Bill was backed by 316 votes to 311, a sharp reduction in his usual 161 majority.
Mr Willis addressed the party's three-day spring conference in Southport as about 20 students braved lashing rain to protest outside at the plans.
In a rallying speech, Mr Willis, who is nursing a sore throat, said when the bill returns to the Commons on 31 March, it would be the "last time" MPs would have to vote the bill down.
"This is a sordid bill. This is a bill that has seen Charles Clarke [education secretary] scurrying around Westminster like Del Boy, promising people dodgy deals to get their support," he said.
"Only the Liberal Democrats have stayed firm to their pledge ... that we actually believe this is an abomination.
"We aren't just opposing this for political opportunism ... if a market is introduced into higher education, by 2010 it will not be possible to move back to a state funded education system."
'Ability to pay'
Mr Willis said by then students would face top up fees in the region of between £10-15,000.
One survey suggested student debts in 2010 would leave with debts topping £33,000.
"Why on earth do we want to saddle students with mortgage style debts when they go to university?" said Mr Willis.
"Tony Blair is destroying the fabric of our education system - ability to pay, not ability to succeed will be the measure of our university system in the future."
Outside the conference hall, students wore balls and chains attached to their feet and a plastic shark with the message 'Hi, I'm Tony' attached to protest at the plans.
Adam Parsons, 19, who is hoping to study politics at Sussex University, said: "I'll have to do some labouring while I'm there if I'm going to have £20-30,000 debt when I leave.
"People won't be able to concentrate on their studies - they will be too busy worrying about how they will pay for them."
Thomas Paul, 19, in his second year studying philosophy at Bristol University, said no-one would be able to trust a political system where a Labour manifesto said it would not introduce top-up fees, but then changes its mind.
"It is really upsetting that a party can go against its manifesto pledge.
"I'm going to leave with £12,000 debt which is more than the total earnings for some families."
The controversial plans will allow universities to charge students up to £3,000-a-year, payable when they earn £15,000.
One of the most controversial aspects of the proposals is the fact these fees can be varied between universities prompting fears that this will put off poorer students from applying to some of the more prestigious institutions.