Religious leaders from across Louisiana complained Friday that the math behind Gov. Bobby Jindal’s tax proposal is flawed.

Northern and Central Louisiana Interfaith, a Shreveport-based religious organization, said the Jindal administration underestimated the expected tax burden on families by omitting part of a proposed state sales tax hike from calculations.

“This is about more than just numbers on a page. This is about integrity and people’s lives,” the Rev. Melvin Rushing, of Baton Rouge, said during a news conference at the State Capitol.

The Rev. Morris Thompson, bishop of the Episcopal Diocese of Louisiana in New Orleans, said the governor should withdraw his sales tax proposal. He was among ministers from around the state drawing attention to the governor’s tax overhaul proposals.

“Our numbers are growing,” Thompson said. “Our voice of justice is being heard.”

The next step, Thompson said, will be to meet with legislators, who will start debating the tax plan in the legislative session that begins April 8.

The Jindal administration refused multiple times Friday to confirm whether a broadening of the state sales tax base was included in a distributed analysis on how Louisiana individuals and families would be affected.

In a prepared statement, Tim Barfield, executive counsel for the state Department of Revenue, said: “More than 80 percent of the expanded sales tax base does not impact families and individuals. That being said, the formula/methodology used to calculate rebates ... ensures that the tax burden will be reduced for all income brackets even when considering increased taxes resulting from an expanded sales tax base.”

Barfield concluded his statement by appearing to blame the ministers’ complaints on misinformation spread by the Louisiana Budget Project, which he called a liberal special interest group.

However, the Louisiana Budget Project is not the only organization questioning the governor’s math.

The Baton Rouge-based Public Affairs Research Council of Louisiana published a report Thursday accusing the governor of using revenue numbers that could knock the budget neutrality of the tax plan out of balance by at least $500 million.

The Council for A Better Louisiana, another public policy organization, warned Friday that low revenues could give legislators no choice but to raise taxes even further.

The governor wants to eliminate the state’s personal income and corporate taxes. To avoid the state budget taking a hit, Jindal wants to replace the revenue by raising state sales tax to 5.88 percent and taxing services that are not currently taxed by the state, including veterinary services, hair cuts and play tickets.

The Jindal administration contends “the vast majority of Louisiana taxpayers will save more through the elimination of state income taxes than they will pay in increased state sales taxes.”

Among the scenarios promoted by the administration is one in which “teachers making $45,000 per year filing individually would see their annual state tax burden reduced by more than $800 on average.”

The ministers said Friday that the administration omitted part of the sales tax increase from its calculation.

Rushing said the administration made no accommodation for the fact that people currently not paying a penny in state sales tax for many services now would pay 5.88 percent. Instead, he said, the administration just included the impact of state sales tax increasing from 4 percent to 5.88 percent.

He said the omission skewed the assessment of how much families would pay.

For several of the religious leaders who crowded into Memorial Hall at the State Capitol on Friday, this was their second trip there. A handful came to the Capitol days earlier to drop off a letter signed by 250 clergy expressing concerns about the tax plan’s impact on the poor and middle class.

On Friday, they returned to the State Capitol with a report detailing their criticism of the Revenue Department’s analysis.