Gov. Phil Murphy and the "dark money" group run by his allies can keep pumping money into television ads promoting a millionaires tax in the next state budget, but it isn't going to convince the state's top lawmaker to support it, he said Thursday.

Murphy has tried to sweeten the pot by dangling a $125 credit to taxpayers if lawmakers support his proposal to raise rates on incomes over $1 million from 8.97 percent to 10.75 percent. But Democratic leaders — who repeatedly and unsuccessfully sought the millionaires tax under former Gov. Chris Christie — have said they no longer support the increase.

“I’m not doing it,’’ Senate President Stephen Sweeney said in an interview, shortly before he met with Murphy and Assembly Speaker Craig Coughlin in Trenton.

Even though the advertisements have not softened Sweeney's position on raising rates on high earners, they have been revealing, Sweeney said, since at least $2.5 million of the Murphy-aligned group's funding came from the New Jersey Education Association.

“He can spend $10 million in TV commercials from the NJEA, because it is crystal-clear who is running Trenton right now — it's not the governor’s office. It’s the headquarters of the NJEA," Sweeney, D-Gloucester, said in the interview.

The education association is the state's largest teachers' union and holds enormous influence in Trenton, particularly with the Murphy administration. It also spent, through an affiliated group, a historic amount in 2017 trying to oust Sweeney in his re-election race.

The union's $2.5 million donation to the Murphy-aligned group, New Direction New Jersey, was revealed only because a non-profit found it in the union's minutes and notified the news media.

Murphy rejected a bill that would have required 501(c)(4) organizations such as New Direction New Jersey to disclose their donors, so it's unknown how many other special interests or businesses may have donated to that group. There is dispute over whether the bill sent to Murphy would apply to such organizations.

New Direction, which is run by Murphy's closest advisers, had said it would disclose its donors but reversed that pledge late last year. Sweeney and Coughlin, D-Middlesex, also have such "dark money" groups supporting them, and they have not disclosed their donors.

Although Murphy has said he supports transparency and prefers that New Direction disclose, he raises money for the organization and is appearing in two new ads pushing for a millionaires tax. Those ads have been paired with email blasts infused with rhetoric promoting a tax increase, saying that "the system is rigged" and must be fixed.

"Donald Trump and Chris Christie teamed up to give the richest of the rich the tax break of a lifetime," an email sent out Monday said. It went on, "supporting the millionaire tax means putting a stop to the exploitation. The rich should pay their fair share so New Jersey can work for everyone, and the middle class can finally get a break on their property taxes."

Representatives for Murphy's office and New Direction New Jersey did not respond for comment.

Hiking the millionaires tax was a key promise of his 2017 campaign for governor, and he asserted that it was central to rebuilding a "stronger and fairer" economy. It's also become a rallying cry for liberal grassroots groups and public employee unions that coalesced around Murphy's candidacy and remain his loyal base of support.

But Sweeney's and Coughlin's resistance forced Murphy to settle for a much smaller tax on income of $5 million or more last year. And that opposition has only intensified this year.

Murphy has little support in the Legislature for the tax hike. All week, Democratic lawmakers have issued statements saying that although they would support a millionaires tax if it came up for a vote, they know it won't happen and they would support a budget that doesn't include the tax.

Murphy hasn't changed position, either, but one side must blink by the end of the month or else the government would shut down without a budget deal to begin the 2020 fiscal year on July 1.

The education association declined to comment but reiterated its support of Murphy's agenda and called him "a champion of middle-class workers and families, including our members."

But Sweeney said those members aren't getting their money's worth with the new ads.

"I was never moving. So they just wasted a bunch of the members' money. Maybe that will prop up Murphy’s numbers or something. Who knows? I don’t know. I could care less," he said.