MADISON, Wis. (CBS 58) -- Assembly Republicans on Thursday released part of their plan to revamp how the state provides aid to local governments.

However, GOP leaders refused to discuss how their proposal will affect Milwaukee. They said that portion of the plan would come out at a second press event later on Thursday afternoon.

The details released Thursday morning at the state Capitol revealed a pledge to have every local community in Wisconsin see its share of state aid increase by at least 10%.

Under a new formula, 20% of all state sales tax revenue would go toward cities and counties. Wisconsin imposes a five-cent sales tax on every dollar spent, with exceptions for certain essential items.

Aside from a new formula, Republican lawmakers said they'd increase shared revenue by $227 million. Currently, the state provides $753 million in annual payments to local governments; that number has been frozen since 2004.

Local governments would have restrictions on how they're able to use that additional funding.

"Those core services are gonna be law enforcement, fire protection, emergency medical services, emergency response communication, public works and transportation," State Rep. Tony Kurtz (R-Wonewoc) said. "The new $227 million needs to be focused in those areas."

Jerry Derr, president of the Wisconsin Towns Association, said the funding increase was long overdue. He added local governments expected there to be mandates on how they could use their new shares of state aid.

"That's always a concern," Derr said. "Of course, there's gonna be hoops to jump through, and there's gonna be some concessions made."

As for additional details in the plan, negotiations are still ongoing. No Senate Republicans were present at the Capitol press event.

Senate Majority Leader Devin LeMahieu (R-Oostburg) said in a statement there had been "good-faith" conversations between the Senate, Assembly and local governments over the past several months, but declined to offer any more specifics.

"The final details are still being worked out," LeMahieu said. "The Senate is looking forward to continuing to find a responsible way to make a generational investment in local governments throughout the state.”

A key question is whether Milwaukee will be allowed to have a city sales tax. A source close to the discussions told CBS 58 the plan will include a Milwaukee sales tax. That source said lawmakers and city officials were still discussing whether a referendum would be required, or if the Common Council could implement the tax with a vote.

The question is what restrictions would apply to Milwaukee, and how the referendum question would be worded.

WisPolitics has reported Milwaukee will only be allowed to use the new sales tax money to pay down pension obligations. Going forward, new city workers would be funneled into the state pension system.

The city would also have to accept state-sanctioned rules for how its Fire and Police Commission is formed, giving more power to police and fire unions. Milwaukee would also be banned from using its sales tax money to extend the streetcar line.

A spokesman for Milwaukee Mayor Cavalier Johnson said the city would not comment until after the second press event later on Thursday.

A spokeswoman for Governor Tony Evers said they hadn't seen enough details to have a response Thursday. Evers told CBS 58 Tuesday it would be a "disappointment" if the plan didn't include a 20% share of sales tax money going to shared revenue, as well as additional local sales tax flexibility for Milwaukee and Milwaukee County.

Assembly Minority Leader Greta Neubauer (D-Racine) declined to answer questions about the proposal Thursday. Instead, her office issued a statement indicating the final proposal was still a work in progress.

"We still haven’t seen a bill draft from the GOP," Neubauer said. "And there is a lot more work to be done to ensure that we have a solution that works for the people of Wisconsin."