The government has been urged by a cross-party group of MPs to delay by at least a year its two-pronged plan to force universities to compete for student places.
In a long-awaited report on the higher education reforms, the Business, Innovation and Skills Committee says that although it was right to end student number controls, it was not possible to achieve change "overnight".
The recommendation from the committee - which has a majority of MPs from the coalition parties - poses a major challenge to ministers, who are planning to make one in four full-time undergraduate places contestable next year.
In its report published on 10 November, the committee points out that David Willetts, the universities and science minister, has himself acknowledged the "destabilising" effect of the reforms, which allow expansion for institutions recruiting top-achieving A-level students or those charging fees of £7,500 or less.
"The minister is right to acknowledge that the government's proposals...will add to the uncertainty currently experienced by universities," it states.
"We therefore recommend that changes to student number controls be deferred for at least 12 months after the reforms to the student finance system have been implemented."
Adrian Bailey, the Labour chair of the committee, said a "fair chunk" of the sector had been calling for the delay while there had been unease "right across the board".
"If [universities] are saying they are going to have great difficulty in making this work, then we as a committee cannot ignore that," he said.
The committee's report says the plan to create 20,000 cut-price "margin" places and increase the number over time seemed likely to "channel an increasing number of people into a low-cost model of higher education", especially students with lower grades.
It raises questions about further education colleges snapping up many of the places and asks the government to "set out clearly" whether this is a "real expansion" or merely a "transfer of provision" from traditional universities to potentially cheaper alternatives.
Elsewhere the report - which has a total of 41 recommendations - criticises the delays to the White Paper, hinting that the government should delay legislation if an adequate suite of policies was not developed.
"We strongly believe that [the reforms] should be implemented as a package and not in a piecemeal way," it says.
Doubt is also cast over the future affordability of the student loan system, with the report stating that "an unprecedented level of uncertainty has been introduced into higher education finances with success dependent on a large number of variables over which the government has little control".
The report raises questions about the way the Browne Review interacted with policy, saying that government statements at the time "appeared to imply that a key purpose of the review, if not its primary purpose, became to find savings...to assist in deficit reduction".
Other recommendations include calling for the government to stop using mean average fees when describing the system, and to focus more on bursaries rather than fee waivers.
Points are also raised about the future involvement of commercial firms in higher education, with a call for clarity about whether they will profit from student loans.
Mr Bailey said his own view was that for-profit providers should not have access to the loans system. "I don't see it is the role of government to provide a subsidy, albeit maybe indirectly, to the private sector," he said.
There is additionally a recommendation in the report that a Quality Assurance Agency review should be triggered when any institution with degree-awarding powers or university title is taken over by another institution or company.
Take time to consider: report's key recommendations
• Changes to student number controls should be "deferred for at least 12 months".
• The government should "set out its long-term aspiration for higher education funding, in the context of improving public finances".
• Contingency measures should be put in place to avoid cuts to student numbers if the system becomes unaffordable to the taxpayer.
• The government should clarify whether commercial firms "will be able to profit directly from tuition-fee income backed by public student loans".
• Changes of ownership of providers with university title or degree-awarding powers "should trigger a QAA review".