City Councilman Carl Stokes says he may go straight to voters this fall to approve cutting the city's property tax rate in half by 2017 — a proposal he said would be paid for, in part, by raising a cap that limits the assessed value that can be taxed.

His tax proposal faces strong opposition from Mayor Stephanie Rawlings-Blake, who says it's unrealistic and would wreck the city's finances. She has a more modest plan to cut the rate on owner-occupied homes by 9 percent over eight years.

If his plan fizzles in the City Council, as it did last year, Stokes says he's "likely" to push for a petition-driven ballot question. Such citizen-led charter amendments are rare in Baltimore; city officials say they believe the last one was in 2002, when voters chose to create single-member council districts.

Stokes said he'll first try to convince fellow council members that his idea has merit. He argues thqat his two-pronged approach, reintroduced Monday as new legislation, would jump-start the economy and be fairer for newer homeowners.

"I think the prospects are a little better than last year," he said. "I don't think, as we speak today, it's clear to my colleagues the impact of this. I think I have work to do, along with others beyond City Hall."

The statewide Homestead Property Tax Credit, as the cap is known, puts a ceiling on how much a property's taxable assessment can rise from one year to the next. The annual cap statewide is 10 percent, but local governments can set theirs lower. Baltimore's has stood at 4 percent for 20 years.

The Baltimore Sun published an investigation last month that revealed the program has grown into a huge subsidy fueling widespread inequality among city homeowners. It also found that errors in billing and inadequate government oversight have deepened the disparities.

The homestead credit now lops off at least 50 percent of the annual tax bills for more than 13,000 city homes, while owners of 25,000 homes — including many recent arrivals — see no benefit from it. This fiscal year, the program has deprived the city of $120 million in tax revenue.

"It's mostly new homeowners who are complaining," Stokes said. He noted that he has no personal gripe: This year he owed just 16 percent of the tax bill on his Barclay rowhouse, thanks to the cumulative effects of the credit and low reassessments on his block two decades ago.

Under Stokes' plan, the annual tax cap would rise to 10 percent over three years and stay there for five years, before dropping back to 4 percent. He wants to mandate that all additional money raised by the increase go to help pay for a steady drop in the tax rate, now the highest in Maryland at $2.268 per $100 of assessed value.

By 2017, he said, his plan would cut the city's rate in half, making it comparable to those in nearby counties. That, Stokes said, would encourage more people and businesses to move to Baltimore, yielding economic benefits similar to those seen years ago in Boston and San Francisco.

To put the question directly on the November ballot, Stokes said he'd need to gather 10,000 signatures by May 31. He has already begun drafting the wording.

Avery Aisenstark, director of the city's Department of Legislative Reference, said it's not uncommon for the City Council to put charter amendments on the ballot. In fact, Stokes introduced his plan Monday as an amendment, meaning it would still go before voters even if approved by the council.

But Aisenstark called it "relatively rare" for citizens to petition for a chance to modify the charter, which Stokes would pursue as Plan B.

The only amendment petition drive that Aisenstark or Armstead Jones, director of the city's Elections Board, could recall in recent years was "Question P" in 2002, which altered the City Council to 14 districts with one representative each and a council president elected citywide.

"You have to get that petition drive going and get those signatures," Jones said. "It takes a lot of work."

Amassing signatures isn't the only hurdle, said City Solicitor George Nilson. The issue must be suitable for a charter amendment and not an ordinary law, which only the council can pass. The line between the two can be murky, he said, and courts have wrestled with it over the years.

The mayor's spokesman, Ryan O'Doherty, dismissed Stokes' plan Monday as a "rehash" from his aborted mayoral campaign last year, contending that it would raise property taxes on longtime homeowners. However, a Sun calculation found that even Stokes would wind up paying less, despite his sizable homestead credit.

"The truth is that Mayor Rawlings-Blake has put forward the only fiscally responsible plan to reduce property taxes for homeowners without drastic cuts in public safety and education funding," O'Doherty said in a statement.

Stokes said he'd like to find someone "completely neutral, who hasn't weighed in before" to produce a study analyzing the likely economic impacts of his proposal.

"The mayor has said to me she's talked to economists who said it would bankrupt the city," he said. "I've talked to economists who have said it would grow the city."

Baltimore Sun reporter Jamie Smith Hopkins contributed to this article.