A lack of Senate support for deregulated fees is expected to fuel debate about other options to increase university revenues, such as increasing the amount that students can be charged while keeping a cap on fees.

Motoring Enthusiast Party senator Ricky Muir said on Wednesday he was "not convinced" the reforms should get through the Senate as they stand. Independent senator Nick Xenophon said he will not vote for fee deregulation, but that he could support temporary fee rises while a root and branch review of university funding is conducted.

Senator Xenophon said such significant change should be taken to an election, a position backed by Senator Muir.

The vice-chancellor of the University of Technology Sydney, Attila Brungs, broke with the sector by telling Fairfax Media he would prefer a cap to remain on fees rather than full fee deregulation.

Although he sided with the government when it presented its reforms to the Senate in December, Senator Muir said at the time: "My vote was not a vote for deregulation. My aim is to continue discussion on university reforms." His stance has hardened over the summer break.

"The government does not necessarily have my support on this," he told Guardian Australia. "I'm really not attracted to these ideas, because I can't vote for something that might make education inaccessible or leave students with unmanageable debts."

In his first appearance since a week on holidays, Prime Minister Tony Abbott said the government would put higher education "front and centre" of the government's agenda when Parliament resumes in February.

The government's reform package is "very important for our universities. It's very important for our future as a creative, dynamic society and economy and that's why we are absolutely persisting with these important reforms", he said.

On current indications, the government would fall at least three votes short of securing a Senate majority for its reforms.

The government needs the support of six of the eight crossbenchers to pass its reforms. Palmer United Party senator Dio Wang personally supports fee deregulation, but the other two PUP members, Clive Palmer and Glenn Lazarus, have spoken out strongly against it. Senator Wang has said he will abide by the party room's decision.

But there is a strong consensus among the Senate crossbenchers that universities face a funding shortfall and additional revenues need to be found.

Professor Brungs said increased student contributions, capped by the government, could boost university revenues while preventing exorbitant fee hikes - an approach backed by economist Bruce Chapman, the architect of the HECS repayment system.

A spokesman for Education Minister Christopher Pyne said: "As we continue to negotiate with the crossbench senators, we do not intend to give a running commentary on specific measures."

Follow us on Twitter