(CNN) - GOP presidential candidate Herman Cain clarified his much talked-about "9-9-9" tax plan Friday, saying those who fall at or beneath the poverty level would have a different plan: "9-0-9."
Cain took heat over his proposal, which replaces the current tax code with a 9% corporate tax, a 9% income tax and a new 9% national sales tax. Opponents have argued the middle part of the plan would increase taxes on the poor, who currently pay little to no taxes.
But Cain fired back Friday, saying in a Detroit speech that those paying no taxes now would continue to pay zero taxes under his plan.
"If you are at or below the poverty level, your plan isn't 9-9-9 it is 9-0-9," Cain said. "Say amen y'all. 9-0-9."
The former Godfather's Pizza CEO also laid out his "opportunity zone" proposal. Under his current plan, businesses would be allowed to deduct purchases from the 9% corporate tax provision. But in cities facing high unemployment–the so-called "opportunity zones"–businesses could also deduct a certain amount of payroll expenses from their corporate taxes.
"One of the things that I believe in is empowering cities to help themselves," Cain said to his audience in Detroit–a city with one of the country's highest unemployment rates. According to the U.S. Bureau of Labor Statistics, Detroit faced a 14.4% jobless rate, not seasonally adjusted, at the end of September.
Cain's tax plan was a heavy target at the last two presidential debates, with other candidates attacking the proposal for being too simple, as well as increasing a new revenue stream under the national sales tax.
But the Georgia businessman, who's now in a tight race with former Massachusetts Gov. Mitt Romney for top choice in national polls, said his plan is simple for a reason.
"Some of my opponents in this race have said 'Why do you want to give government another mechanism to tax us?' My response is: I want to take away the 10 million other ways they have now," Cain said. "I'm not worried about one, I'm worried about the 10 million in the current tax code."
As Cain has surged to the top of the race in recent weeks, his plan has been vetted by numerous economists
A check of the figures on CNN's "John King, USA" found a significant gap in revenue between Cain's plan, which would bring in $1.77 trillion in revenue, and the current tax structure, which brings in about $2.16 trillion.
But the candidate insists he could get the plan passed through Congress under a Cain administration.
"Bottom line folks, 9-9-9 means jobs jobs jobs," Cain said. "Let's renew the economy of this nation."