Updated at 3:30 p.m. to include additional commentary from Democratic Reps. Chris Turner, Eddie Rodriguez and Trey Martinez Fischer.

AUSTIN — Texas' top lawmakers unveiled Thursday what's likely to be a hotly contested piece of legislation this year — a proposal that offers property owners modest tax relief by imposing onerous restrictions on school district and local government budgets.

Advocates of the caps say they're necessary to keep skyrocketing property tax bills from climbing at unsustainable rates for home and business owners. But opponents say the caps are an overreach of state government, which would handcuff mayors, city councils and school board members who rely on local property taxes to pay for critical services like fixing roads and paying police and firefighters.

In a show of unity between the two legislative chambers, Sen. Paul Bettencourt, R-Houston, and Rep. Dustin Burrows, R-Lubbock, filed identical companion bills capping property tax revenue growth at 2.5 percent a year for local taxing entities. Bettencourt and Burrows chair the Senate and House committees in which the property tax bills will first be debated.

Lt. Gov. Dan Patrick said homeowners who routinely bemoan the annual spikes in their property tax bills — which sometimes jump as much as 6 percent or more every year — will get relief with this legislation. From 2013 to 2017, the average property tax bill in Dallas increased 33 percent.

"Those days are over," Patrick said during a news conference with House Speaker Dennis Bonnen, Gov. Greg Abbott and the two bill sponsors.

Notably, the plan is not expected to reduce tax bills for property owners — rather, it would slow the speed at which they increase year over year.

Tax caps

Local governments and school districts largely rely on property taxes to fund their services. This bill would effectively force local governments and school districts to set lower property tax rates to ensure they can't collect more than 2.5 percent in property tax revenue than they did the previous year.

The bill largely mirrors Abbott's property tax plan, on which he campaigned ahead of his November re-election.

For school districts, lawmakers have promised additional legislation that would provide state dollars to replace every local dollar they lose because of the property tax cap.

Democrats on Thursday pounced on the fact that the current bill doesn't include that safety net.

"It's unclear if the state will even live up to that commitment because it's not embedded in the filed version [of the bill]," said Rep. Trey Martinez Fischer, D-San Antonio, a member of the Ways and Means committee that will debate the House bill.

City and county governments, as well as special taxing districts that fund hospitals, utilities and community colleges, would not receive state dollars to supplant lost revenue. Instead, they're being asked to tighten their belts.

If local governments want to exceed the cap, they'd have to get voter approval. The tax elections could be held only in November, when voter turnout is greatest.

Currently, local taxing entities, excluding school districts, can increase property tax revenue by up to 8 percent every year, without an election.

Dallas Rep. Chris Turner, chair of the Texas House Democratic Caucus, said the answer to high property taxes is to change school funding so it's not as reliant on property taxes.

"School taxes are more than half the total property tax burden in Texas," Turner said. "An arbitrary revenue cap, one that will also make it more difficult for local communities to fund public safety, is not going to solve this problem."

'Uphill battle'

But curbing skyrocketing property taxes was a campaign promise of many Texas Republicans who ran for office last year.

In the 2017 legislative session, the House and the Senate fought over whether to set a 6 percent or 4 percent property tax cap. Both plans died.

At the news conference Thursday, Bettencourt made light of the fact that the new plan, which originated from Abbott's campaign promise, was a harder reach than both plans that were rejected two years ago.

"That number came from the governor who wisely determined with the House at 6 and the Senate at 4 he was going to compromise at 2.5 [percent], and that's what's called real leadership," he said.

The difference this year, the bill sponsors said, is that the House and Senate leadership are united. Each chamber is starting from the same place with the same bill. The bill is expected to fly through the Senate property tax committee, where four out of five members are co-sponsors.

But opponents of the caps point out that another key difference is that a dozen more Democrats, who were ushered into the House with the November election, are likely to reinforce that opposition.

Rep. Eddie Rodriguez, D-Austin, said 2.5 percent is a "nonstarter" for him and doesn't believe there's any will in the House to get anywhere near that low of a cap.

"With 12 new Democrats, it seems like a pretty uphill battle," he said.