Eight members of the Young Nationals tried to close the association's meeting on Thursday afternoon during debate on Sir Roger Douglas' Education Amendment Bill, which aims to impose voluntary student membership.
They were among 200 OUSA members at the meeting.
The group attempted to disrupt debate and prevent a vote on the issue by calling a quorum count, and noisily left the meeting room during a speech.
The remaining students booed and yelled "shame" as the Young Nationals delegates departed.
The speech was allowed to continue, after which a count showed a quorum.
A motion was put forward: "That OUSA actively opposes Sir Roger Douglas' Education (Freedom of Association) Amendment Bill and believes that only universal student membership can provide the association with the ability to adequately represent and support its members".
Association president Edwin Darlow said the proposal was passed with overwhelming support.
He was pleased it passed, because the Bill had the potential to impact negatively on students.
He likened student associations to local authorities, or the Government, which levied rates or taxes to provide services.
"Everyone has to pay rates, or taxes, in return for the services and representation they receive. Not everyone uses those services . . . but they are valuable services available to all.
"If [our membership] is made voluntary, you would have to ask whether people should have to pay rates or taxes," he said.
The association also approved the draft 2010 OUSA budget, which showed it would go into the red next year to retain its existing level of services and financial support to students.
While the organisation wanted to break even, the executive decided to approve a deficit of just over $89,000 in its operational budget.
