The cost of applying for a divorce has dramatically increased after the government rushed through a regulation in defiance of the Senate.

On the last day of parliamentary sittings before the six-week recess, the Senate shot down a regulation that would have restructured fees for the family court and federal circuit court.

Those changes were due for 1 July, and would have given the government a $87.4m windfall had it not been disallowed by the Senate.

On Sunday, the government reintroduced similar regulations that would take effect the next day. As of Monday, the cost of applying for a divorce went up from $845 to $1,200. Concession card holders will continue to pay a reduced rate of $280.

The cost of issuing a subpoena has gone up from $55 to $125, and amending an application, which was previously free, will now cost $125. Opponents of the price rise have dubbed it a “divorce tax”.

A spokesman for attorney general George Brandis said the budget measure was “critical to ensuring that the courts are placed on a sustainable funding footing”. It would “enhance the courts’ capacity to provide services to families and other litigants”, he said.

Opposition parliamentary secretary Graham Perrett told Guardian Australia he was furious over the changes, blaming “government trickery”.

“This shows that Brandis and [prime minister Tony] Abbott will stop at nothing,” he said. “They snub their nose at our democracy, because the Senate made its intention clear.”

The Greens spokeswoman for legal affairs, Penny Wright, said the new regulationshowed the government was taking a “chaotic and bloody-minded approach by trying to ram through price increases”.

“This government is increasingly contemptuous of the rule of law,” she told Guardian Australia.

But a question mark remains over the legality of the new regulation. Once regulation is disallowed by the Senate, similar regulation cannot lawfully be made again within six months.

A spokesman for Brandis said the regulation was substantially different from the previous one because the fees listed were higher than those in the June regulation. The cost of all services has increased by an additional $5.



The Greens will look into disallowing the new regulation when the Senate resumes in August, but it is unclear what will happen to applicants in the interim.

People who lodged applications in the family or federal circuit courts before Monday have until 24 July to pay the old fees. Anyone who applied after 13 July will be subject to the new prices.

The Community and Public Sector union (CPSU) said it was worried that its members who staff the courts might be subjected to intimidation or violence after applicants find out about the new fees.

“Family court staff have been caught completely off guard by this price hike because there was absolutely no forewarning about the change. The fee increases were scheduled for 1 July, then they were off, now staff have suddenly found out this week they are on again immediately,” CPSU national president Alistair Waters said.



“The family court staff already have a very stressful and difficult job, given the often painful family issues dealt with by the court,” he said. “Staff and families using the court do not need the added stress of being hit with unexpected extra charges.”

Labor and the Greens have expressed concerns that the price rises will adversely affect the most vulnerable women in society, such as those trying to leave domestic violence situations.