DES MOINES, Iowa (AP) — Iowa Senate Republicans used a procedural maneuver last week to fast-track votes on a sweeping tax overhaul bill that national experts say could limit transparency and public engagement at the state Capitol.

The legislation would reduce taxes by more than $1 billion annually, in part by cutting corporate and individual income taxes and eliminating some tax credits. The Republican senator who authored the bill said Thursday he didn't yet have a five-year projection on its fiscal impact to the state's roughly $7.2 billion budget, but the measure is moving through the legislative process quickly.

The bill was released publicly Wednesday morning. A little over 24 hours later, it had advanced through a tax-writing subcommittee and a full committee. At one of those meetings, lobbyists for various organizations indicated they hadn't read all of the bill's roughly 130 pages. A Senate floor vote is expected as soon as this week.

Alex Howard, deputy director for the nonpartisan, open-government watchdog Sunlight Foundation, said there are reasons bills can move swiftly if there are emergency circumstances and the legislation is straightforward, but this doesn't seem to be the case with the Iowa tax bill.

"The more complicated the legislation becomes and the more far reaching it is, the more it makes sense to look at how much time there is for the public to fully understand and digest it," he said.

Sen. Randy Feenstra, a Hull Republican and the bill's author, defended the move to suspend rules and advance the legislation through a subcommittee and committee on the same day. He told The Associated Press via email: "This procedure is utilized frequently in Senate Committees."

That argument requires context. Few bills advance so quickly unless there's a looming legislative deadline known as funnel week, which requires legislation to have a threshold of votes to stay alive for the session.

There have been several instances over the years in the Senate and House, under both Republican and Democratic control, where a panel approves a bill in the morning with then a full committee vote a few hours later. There are also instances when lawmakers suspend rules to hold a subcommittee within a committee meeting.

Dan Beverly, executive director of the nonpartisan National Freedom of Information Coalition, said allowing lawmakers to repeatedly suspend existing rules, particularly with same day votes, sets bad precedent.

"If you're not consistent with the rules, you really don't have rules," he said.

Sen. Rob Hogg, a Cedar Rapids Democrat, said tax-related bills aren't even subject to the legislative deadline that drives many of those other scenarios. He also pointed to last year, when the new Republican-controlled Legislature publicly released a 68-page bill on Feb. 7 that eliminated most collective bargaining rights for many public workers. The legislation advanced quickly in both chambers through existing chamber rules. Former Gov. Terry Branstad signed the measure into law on Feb. 17.

"They've shown they have the ability to ignore public input and steamroller the legislative process," Hogg said of Republicans.

The Iowa Senate GOP tax bill would cut the state's top corporate tax rate from 12 percent to 7 percent. The top individual income tax rate would drop from 8.98 percent to 6.3 percent.

It's unclear how the tax cuts would impact government services. The Legislature is currently debating mid-year budget cuts for state agencies and higher education amid lower than expected revenue growth. Lawmakers made similar decisions last year and eventually borrowed about $144 million from emergency reserves. Lawmakers plan to pay that back.

Feenstra said Thursday: "I can assure you the bill is fiscally responsible." He said there will be a nonpartisan fiscal analysis before a floor Senate vote.

Data indicates the state could see some revenue increases soon, in part because of the new federal tax cuts. Details are still being sorted out.

Still, the reality of budget constraints is one reason GOP Gov. Kim Reynolds released a tax plan earlier this month that isn't as expansive.

Reynolds doesn't cut corporate tax rates or remove tax credits, arguing she'd like to study the issue further. Reynolds also proposes tax cuts of $1.7 billion over several years, a smaller price tag that will also need more review. There are some similarities, like eliminating a longstanding federal deductibility provision. Both bills also expand taxes on online sales and allow tax-free savings accounts for private K-12 education.

House Republicans are expected to slow the process.

House Speaker Linda Upmeyer, a Clear Lake Republican, said Thursday her caucus will work off Reynolds' bill. Senate Republicans, who argue without evidence that their "bold" plan will spur economic growth, acknowledge they expect negotiations within their party.

Neither Upmeyer nor Reynolds' staff would comment on the legislative speed of the Senate Republican bill. However, Upmeyer said House Republicans could debate tax cuts in the weeks ahead while considering spending cuts and the next state budget.

"I think you can do both things at once," she said. "You just have to be thoughtful about it."