State lawmakers shuffled the legislative calendar Thursday to give more time to fix thorny problems in a proposed tax reform plan.

House and Senate Republicans worked on their own versions of the plan throughout the day, but were unable to reach an agreement.

“The effort is still ongoing, but I wouldn’t characterize us as close,” House Majority Leader Larry O’Neal, R-Bonaire, said.

A House vote on HB 387 had been planned Wednesday until concerns over impact of the proposed changes on middle-class taxpayers emerged.

House Minority Leader Stacey Abrams, D-Atlanta, relaunched the debate over the bill with a spreadsheet developed by Georgia State University economist David Sjoquist showing that the planned cut in the personal income tax rate from 6 percent to 4.5 percent actually would increase taxes on many taxpayers. Taxpayers with taxable incomes between $20,000 and $180,000 would be hit with hundreds in new taxes, while higher-income taxpayers would receive a substantial cut in their taxes.

The news attracted renewed criticism of the bill from conservative causes -- such as the Georgia Tea Party Patriots and Americans for Prosperity -- which worry Georgians would end up paying more in taxes. But it also drew new criticism from religious and charitable groups because the plan would do away with most deductions, including those for charitable giving.

House Speaker Pro Tem Jan Jones, R-Milton, said she believed a reworked plan would address those concerns.

“We’re trying to make accommodations for Georgians,” she said. “Not special interests, but Georgians.”

Republicans shelved efforts to pass the bill this week, rescheduling Friday’s planned workday until April 11. If the House passes the bill on that day, it will give the Senate just enough time to vote on it on the final day of the session.

That tight timeline worries House Minority Caucus Chairman Brian Thomas, D-Lilburn.

“This is big picture stuff, changing the tax code,” he said. “They [Republicans] didn’t put any work into understanding it. We had to point out the problems with it.”

Jones said changes being worked on in private meetings with Republican lawmakers would protect most low- and middle-income taxpayers from paying more taxes. She would not give details of the proposal.

House Republicans held one of those meetings Thursday afternoon, with House Speaker David Ralston, R-Blue Ridge, speaking and taking questions from members for about 30 minutes. O'Neal said it was an informational meeting.

Ralston has defended the plan, saying the proposed tax changes would draw new jobs.

Thursday evening, Ralston had unusually harsh words for the new system of leadership in the Senate as hampering negotiations over the tax plan.

“I have tried this session to avoid meddling in the business of the Senate, but we have come perilously close to their little experiment over there harming the people of Georgia,” Ralston said. “We can’t have 36 different leaders or however many they have on any particular day. The internal problems are getting in the way of work.”

A move to change Senate rules by Sen. George Hooks, D-Americus, which could have opened the door to restore power that had been stripped from Lt. Gov. Casey Cagle, took up part of Thursday, but the effort failed.

As for the tax plan, O’Neal said lawmakers are working on several complex issues he believes will result in virtually every taxpayer paying the same or getting a tax cut from the plan.

Senate Democratic Caucus Chairman Doug Stoner, D-Smyrna, declared the package of reforms "a pig in a poke."

"They really have provided no information on what is in their tax proposal," he said.

Sen. Don Balfour, R-Snellville, said he's confident that an agreement can be worked out. Balfour said one proposal would phase in an energy exemption over a number of years to pay for tax relief for the middle class.

Stoner is challenging every senator to sign a pledge not to raise taxes on the middle class.

"First we want to take HOPE away from the middle class, and now we are raising their taxes," he said.

Apart from lowering the income tax rate, the plan would give tax breaks to industry and agriculture, charge the state sales tax to automotive services, charge a 7 percent tax on satellite television and Internet phone service, and tax the private sales of cars, among other provisions.

Staff writers Jim Galloway, April Hunt and Christopher Quinn contributed to this article.