Labour backbenchers followed Harriet Harman in taking the tuition fees fight to Nick Clegg in this week's prime minister's questions.
The Liberal Democrat leader was repeatedly confronted with his decision to break a pre-election promise that students' fees would not rise.
Ms Harman, Labour's deputy leader, received a huge laugh when she suggested Mr Clegg's behaviour resembled that of a student in fresher's week where "you meet a dodgy bloke and you do things that you regret".
She accused Mr Clegg of going along with a "Tory plan to shove the cost of higher education on to students and their families".
The deputy prime minister responded by pointing out Labour had broken election manifesto promises on higher education funding in 1997 and 2001.
He attacked Ms Harman's support for the graduate tax proposal, which has been mooted by business secretary Vince Cable only a few months earlier but was rejected after the Browne review found it to be unworkable.
Opposition MPs reacted with scorn when he insisted that the plans to hike tuition fees to £9,000 were an improvement on Labour's system.
"Proposals we have put forward will mean those who earn the least will pay much less than they do at the moment," he argued.
"It is a fair and progressive solution to a very difficult problem... before the election we didn't know the unholy mess that was going to be left to us by her party."
Labour backbenchers including Gavin Shuker, Emily Thornberry and Tom Blenkinsop were among those adding pressure to Mr Clegg on the issue.
He received assistance from his own party from Stephen Lloyd, who gave his party leader the opportunity to praise the Lib Dems' pupil premium now being implemented.
But malcontent Tim Farron added to the focus on higher education with a question about teacher training, in a move which may be viewed as unhelpful by the party whips.