PHOENIX — Republicans who hold the majority in the Arizona Legislature are working to strike a final deal with Democratic Gov. Katie Hobbs and leaders of cities, counties and tribes in metro Phoenix over an extension of a transportation tax that has funded massive expansions of the region’s freeway and roads system, bus routes and the light rail over nearly four decades.

And the outcome of those talks has statewide implications.

Failure to get a plan out of the Legislature that the governor will sign — and can win support from voters in Maricopa County next year to extend the half-cent sales tax for another 20 years — would affect all of Arizona.

That’s because the regional planning agency called the Maricopa Association of Governments funds its own projects outside the state general fund using the sales tax proceeds which will average about $1 billion a year over the coming 20 years. If the tax goes away, transportation projects in the other 14 counties would suddenly be competing for limited state transportation dollars with a county that is home to nearly two-thirds of Arizonans.

The lack of an agreement remains the sole major issue remaining for the Legislature to address in this year’s highly unusual session, which has seen multiple prolonged breaks, including one that will have stretched nearly seven weeks when lawmakers return next Monday. Hobbs vetoed the Legislature’s extension plan in June, siding with the group known as MAG, whose plan was eviscerated by GOP lawmakers.

Republican House Speaker Ben Toma told Capitol Media Services that the plan is to adjourn for the year the day the Legislature returns on Monday, with a potential deal on extending Proposition 400 and what he called some “administrative types of things” all that remains to be accomplished.

He and GOP Senate President Warren Petersen both said there’s been progress on settling the Proposition 400 extension but stopped short of proclaiming a breakthrough.

But Sen. Ken Bennett, R-Prescott, said he’s been told a tentative deal is in place but that bill language still needs to be finalized.

That squares with Toma’s statement that MAG has to come back with an acceptable response for a deal to happen.

“Unfortunately, I can’t tell you if we’re going to have the deal or not yet, at this point,” Toma said in an interview late last week. “We’ve been waiting for a response back from MAG, and my understanding is they’re waiting for input from some of their people before they respond to us.”

Getting Toma on board is critical, since new House rules adopted in January by majority Republicans say the speaker must sign off on all legislation before it goes up for a vote.

“The starting point is really they have to bring us back language or something that we can get the votes for — and I guess to be blunt, starting with mine,” he said. “So if they can’t get my vote, I’m not sure how they’re going to get any others at this point.”

Hobbs spokesman Christian Slater declined to comment on the status of negotiations. Neither did a spokeswoman for MAG. Requests for comment from new MAG chair Kate Gallego, mayor of Phoenix, were not immediately answered.

Gallego, who took over as MAG chair from Avondale Mayor Kenn Weise last month, said in a news release after being elected as the group’s leader that extending Proposition 400 was a top priority.

“Our most pressing priority is to give voters the power to shape their transportation future through the extension of Proposition 400,” Gallego’s statement said. “The regional strategic transportation infrastructure investment plan is critical to propelling our region forward and to our continued prosperity.”

Toma said finalizing a deal is in the hands of MAG.

“I’ve made it pretty clear to them what it’s going to take,” Toma said. “So it’s a question of whether or not they want to take that seriously and if they want the deal for them or not.”

Hobbs took over the lead in negotiations for the sales tax extension in late May, shortly after she signed a state budget for the fiscal year that began July 1 that she had negotiated with Republican lawmakers.

Rather than adjourn for the year, GOP leaders kept lawmakers in session after the budget was enacted, mainly to keep up pressure on the governor, the first Democrat to hold the office in nearly 15 years.

Hobbs decision to directly negotiate with the Legislature came after MAG failed to persuade Republican lawmakers to back their plan.

Those talks failed to lead to an agreement that would pass muster with the 27 mayors, three tribes and two counties who lead MAG. On June 20, the governor vetoed the measure that passed with only GOP support and would have asked voters to extend the sales tax.

The proposal Republicans sent to Hobbs dedicated much more of the estimated $20 billion the sales tax will collect over 20 years to freeway and major road building and maintenance than MAG’s plan. Their plan also slashed the portion of the revenue that went to public transit and barred any of it from being spent to extend the metro area’s light rail system. They also split the extension vote into two parts, one for the road and highway projects and one for light rail maintenance.

Also tucked into the GOP-passed plan was a provision requiring the Arizona Department of Transportation to set the speed limit on all Maricopa County freeways at 65 MPH or more. That’s designed to eliminate a 55 MPH limit on the portion of Interstate 17 between the Capitol and Dunlap Avenue.

Toma said that was included at the request of several GOP House members, although he backs the idea because traffic on that stretch is already going that fast anyway.

“In that whole section if there’s no traffic, everybody’s going 70-75 (MPH) still or more as they’re coming into the Capitol,” Toma said. “So it’s almost just bringing it to the reality of what is happening on the road.”

Getting a deal on Proposition 400 done in the one day the Legislature plans to be in session next week would be unusual, but Toma said it can be done.

“And secondly, there’s nothing precluding the governor from calling a special session if she so chose, and if we have a deal,” Toma said. “So that’s always a possibility. The point is less about the technical ‘how we do it,’ and more about whether or not there’s a deal.”

Rep. David Cook, R-Globe, who chairs the House Transportation Committee, said Tuesday that he’s been pushing Toma and Petersen to work out a deal with Hobbs and MAG, and that the agreement is “95% done.”

“I can’t in my position get the 5% done with the governor and the Senate and the House,” he said. “It’s going to take those elected leaders to do that.”

Weise, who led MAG until Gallego rotated into the chair spot last month, also said the solution must come from the House and Senate leaders and Hobbs. Business groups that normally have the ear of GOP lawmakers have pressed without success to get Republicans to back MAG’s plan.

“I think movement’s going to come about from pressure,” Weise said.

“I think there are moderate Republicans and Democrats that want to get this done,” he said. “They’re the ones that are going to have to put pressure on leadership to get this done.”

Bennett said he’s prepared to get more involved if Toma and Petersen fail.

“I absolutely want to come back Monday with a deal,” Bennett said. “And if leadership and the governor and MAG haven’t been able to come to a deal then I might have some meetings with all the right people if I can to see what’s keeping us from a deal.”

Bennett has some history, having headed the Senate the last time it approved sending the Maricopa County transit tax to voters.

“I had to force a deal 20 years ago when I was (Senate) president, and somebody needs to do that again,” he said.