Palmer United Party senator Glenn Lazarus has told Education Minister Christopher Pyne to "stop harassing" him over the Government's contentious overhaul to the university sector, saying the changes are "bad to the core".

His statement means the changes are destined to fail in the Senate, where the Government has been trying to secure the six votes it needs from the crossbench.

The Government wants to cut funding for courses by 20 per cent but allow universities to set their own fees.

Mr Pyne this afternoon announced further changes in a last-ditch attempt to get the crossbench to support the bill.

He said the Government would set up a structural adjustment package to help universities that enrol a higher number of disadvantaged students.

He also gave a commitment that domestic student fees will be lower than international students.

At this stage the Government's plans are facing almost certain defeat because four crossbench senators have declared their opposition to it.

Senator Lazarus said he and fellow PUP senator Dio Wang would vote against the changes.

"Christopher Pyne is embarrassing himself and needs to stop harassing me and other crossbenchers," the former State of Origin star said in a statement.

"I am being inundated with text messages from Christopher Pyne virtually begging me to support the Abbott Government's higher education reforms."

He said the Government had offered "all sorts of deals" to secure his support, but said he "won't be bought".

Breakdown of crossbench votes The Government needs six of the eight crossbench votes to pass the legislation. Definite No: Independent senator Nick Xenophon

Independent senator Nick Xenophon Independent senator Jacqui Lambie

Independent senator Jacqui Lambie Palmer United Party senator Dio Wang

Palmer United Party senator Dio Wang Palmer United Party senator Glenn Lazarus Leaning Yes: Liberal Democrat senator David Leyonhjelm

Liberal Democrat senator David Leyonhjelm Family First senator Bob Day

Family First senator Bob Day Independent senator John Madigan Unclear: Motoring Enthusiast Party senator Ricky Muir

"I am not prepared to horse trade," he said.

"The higher education reforms are nothing more than a sinister Abbott Government budget cutting measure.

"The Abbott Government's higher education reforms are bad to the core and will only significantly reduce funding to universities, which in turn will significantly increase the cost of higher education in Australia."

Opposition Leader Bill Shorten has seized on the comment in Parliament.

"No amount of unsought attention from the Minister for Education, no amount of demon dialling from the worst education minister in federation history, changes a bad and rotten set of proposals," he said.

Earlier today, Mr Pyne said he was "very patiently" trying to address each issue that has been raised by each crossbench senator, and was making progress.

"I'm certainly getting closer and closer," he said.

"It's like wading through molasses because we have eight crossbenchers."

The minister yesterday announced he had conceded to crossbench demands, retaining the student interest rate at the consumer price index instead of lifting it to the higher bond rate.

The Government has also agreed to a proposal from Victorian senator John Madigan to give students who are new parents a five-year interest pause.

Lambie says Government's overhaul 'all over'

But independent senators Jacqui Lambie and South Australian Nick Xenophon are also opposed to the changes, meaning the six crossbench votes are out of reach.

Senator Lambie declared earlier today that it was "all over" for the Federal Government's higher education overhaul, and urged other crossbench senators to vote down the package.

Yesterday Prime Minister Tony Abbott said the Government was "determined" to have the legislation dealt with "one way or another" this week, the final parliamentary sitting week of the year.

The vote was delayed by a procedural manoeuvre instigated by Labor in the Senate last night, which means other legislation needs to be debated and dealt with first.

Independent South Australian senator Nick Xenophon this morning confirmed he "can't" support the changes.

"I think we need to move very cautiously on this," Senator Xenophon told Radio National.

"These changes aren't due to come into force until 2016. There's still time.

"I think the sector needs to know one way or another what's happened by early next year."

Senator Lambie urged Victorian crossbencher Ricky Muir - who is nominally part of the PUP bloc - to oppose the legislation.

"I am concerned maybe the Coalition has got the better of him," she said.

"I wanted to remind Ricky of his humble beginnings and that in six years' time, like the rest of us, he may not have his seat," she said.

"He has four or five children and I am sure he would like to see them have the opportunity of going to university.

"Putting that many kids through university will cost a fortune and it will be outside what he can afford if that be the case."

Senator Muir was peppered with questions about the issue at an event to discuss safe driving this morning, but did not answer.

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"We're not here to speak about that," he said.

"Today we're here to speak about the automotive industry.

"We're not here to speak about higher education today."

In October, PUP leader Clive Palmer declared "bye bye" to the education changes, but has more recently indicated the legislation could win PUP support with amendments.