Student unions at Carleton University are asking a judge for help after the Ottawa school's administration decided to withhold their membership fees.

The Carleton University Students' Association, or CUSA, and the Graduate Students' Association (GSA) said Thursday that the university is withholding their fees to force the groups into signing new funding agreements.

"The university collected this money on behalf of the students' unions and has no right to withhold our democratically decided membership fees," CUSA president Alex Sirois said in a release. "Membership fees are our sole source of operating revenue. Without these fees, we won't be able to offer services."

The unions said the decision to withhold their fees was passed late last month at the university's board of governors, despite attempts to negotiate in good faith and the unions "making concessions that address all of the university's stated concerns."

The university has demanded financial control over the unions, which could threaten their autonomy and increase the university's "exposure to liability," they said.

The unions said the university is striking back for criticism it has received on a number of issues.

"The claim that this is about financial accountability is a red herring," GSA president Kimalee Philip said in a release. "This is about political interference, plain and simple. They want to silence students' voices on-campus."

The two unions filed a lawsuit in Ontario Superior Court on Wednesday asking for their fees to be handed over immediately. However, the case isn't scheduled to be heard until March.

Carleton University spokesman Jason MacDonald said the university is not trying to dictate how the unions spend the estimated $7 million that has been collected, but is asking that they be accountable for the money.

MacDonald said the university asked the unions for audited financial statements a year ago, but they have resisted.

"The university has no interest in determining or directing how student associations at Carleton University spend their funds," MacDonald said in an email. "The university is simply asking for CUSA and GSA to be transparent and accountable to the Carleton community with regard to how student fees are disbursed."

MacDonald said no groups have been denied money to operate any of their services.