The Senate has voted down government legislation that would have forced university students to pay $250 a year to help fund campus services.

The draft laws sought to wind back voluntary student unionism which was introduced by the previous Howard government.

The government claimed the annual charge did not amount to compulsory student unionism because any money universities collected could not be used for political purposes.

"This is a fee to assist the rebuilding and the restoration of student services and amenities and is not for student organisations," Labor frontbencher Kim Carr said before Tuesday's vote.

But Liberal senator Brett Mason said modern Australian students were older, often working and didn't have the time or inclination to use such services.

"We do not believe that students should be forced to pay for services they will not or cannot use," he said.

Family First senator Steve Fielding said the fee was nothing but an extra tax.

"Students are struggling to make ends meet and we should not be putting an extra financial burden on them at all," he said.

The draft laws did however get the support of the Australian Greens and Independent senator Nick Xenophon.

"I think that (the bill) is far from perfect but it's better than the situation now," Greens senator Sarah Hanson-Young said.

The Higher Education Legislation Amendment (Student Services and Amenities and Other Measures) Bill 2009 was tied 34 votes to 34.

Because the vote was tied, the bill was defeated.