When Oklahoma educators headed back to school in mid-April after their historic nine-day walkout, they did so with mixed feelings. They hadn’t won all of their key legislative demands, but they didn’t return empty handed either: Teachers won salary increases of roughly $6,100 each, and raises of $1,250 for school support staff.

The pay increases, set to take effect August 1, would be paid for by new taxes on cigarettes, motor fuel, and oil and gas production. “We achieved something that we all thought might be impossible,” Oklahoma Gov. Mary Fallin (R) said when she signed the tax legislation into law.

But some conservative activists are saying, “not so fast.”

Members of Oklahoma Taxpayers Unite, an anti-tax group, filed paperwork last week to get a veto referendum on the November ballot. The group has until July 18th to collect about 41,000 signatures. The new taxes to fund the salary increases are scheduled to go into effect on July 1, but there’s debate over whether those would need to be put on hold if activists collect enough ballot signatures before that date.

A representative from Oklahoma Taxpayers Unite did not return Rewire.News‘ request for comment, but a member of the group, Ronda Vuillemont-Smith, told Oklahoma’s local NBC affiliate that they “believe very much that teachers need a pay raise” and that her group’s ballot initiative is “not personal.” Vuillemont-Smith argued that legislators should conduct statewide audits to eliminate waste from agency budgets before raising taxes.

Ed Allen, president of the Oklahoma City American Federation of Teachers, told Rewire.News there’d be “no way” the referendum would pass if it were voted on today. “There’s zero chance, I’d put big money on that,” he said. But Allen acknowledged that “a lot of things could happen between now and November” as anti-tax groups start raising money and doing advertising. “It’s a shame that we have to spend some of our attention and resources on defeating this when we want to defeat those representatives who don’t lift a finger to help education,” he said.

The Oklahoma Education Association (OEA), the largest teacher union in the state, is gearing up to fight the ballot initiative.

Lawyers for the union believe the salary increases are locked in, and the veto referendum addresses only a funding mechanism for those raises. But a provision in the teacher pay bill stipulates it will not become law unless items from the tax increase bill are enacted.

“There are probably going to be conflicting views on this,” an OEA attorney told the Associated Press. “At the end of the day we’ll need some determination, from either the courts or the attorney general.”

Educators did manage to stave off a separate challenge last week, defeating what some public education advocates were calling a Republican “revenge bill.”

Taking aim at a bill designed to protect children from abuse and neglect, Oklahoma state Rep. Todd Russ (R-Cordell) introduced a last-minute amendment to prevent school districts from automatically deducting union dues from teacher paychecks. Educators instead would need to make other arrangements to handle membership payments. Russ’s amendment would have also mandated that a majority of educators in each school district vote every five years on whether they want to keep their collective bargaining unit; if a majority did not vote in favor, the school district would be stripped of union representation.

Doug Folks, a spokesperson for OEA, told Rewire.News that teachers, police officers, firefighters, and state workers inundated legislators’ phone systems and “in about 18 hours, we were able to get enough promises of no votes that the [amendment] was never heard.” The bill, SB 1150, was approved by lawmakers without the anti-union provisions. It now awaits the governor’s approval.

It wasn’t the first time state Rep. Russ has introduced legislative language like that and union leaders say they would not be surprised if he tries again in the future. “He’s just union-busting,” said Allen. “Plain and simple.”

Russ did not return Rewire.News’ request for comment, but he told NewsOk that he was looking out to protect teacher fairness.

State Rep. Forrest Bennett, a first-term Democrat representing Oklahoma City, told Rewire.News he did view Russ’s amendment as strike retribution on the part of the GOP leadership.

“Those of my colleagues in the legislature who are frustrated with teachers and other education advocates are showing their true colors,” he said. “They’re saying they are frustrated with the ‘tactics’ of the teachers and the unions, but in reality I think they’re pretty sore from being exposed. For years, legislators have been able to go home to their constituents and claim they’re all for education. But teachers across the state learned that their legislators talk about better schools out of one side of their mouth and then advocate for tax cuts out of the other. We can’t fund core services like education while we cut, cut, cut.”