Republican presidential candidate Ben Carson is using the Bible to support his proposal to impose a flat tax plan wherein both the rich and the poor pay an equal percentage of taxes from their income.

According to Carson, the measure was inspired by the Biblical practice of tithing.

"I like the idea of a proportional tax - that way you pay according to your ability. I got that idea quite frankly from the Bible. You make $10 billion a year, you pay a billion; you make $10 year, you pay one. That's pretty damn fair if you ask me," he said on Fox News Sunday.

Carson, a former neurosurgeon who recently announced his candidacy for the presidency, debunked criticism that his tax measure could adversely affect the poor, saying that based on his experience of growing up in poverty, poor people have their pride too.

"Now, some people say it's not fair because, you know, the poor people can't afford to pay that dollar. That's very condescending. You know, I grew up very poor. I've experienced every economic level. And I can tell you that poor people have pride, too. And they don't want to be just taken care of," Carson said.

Peter Coy, the economics editor of Bloomberg Businessweek, said Carson's position on his planned flat tax is vague as he did not discuss measures that could cushion its impact on the low income earners.

"One thing is indisputable: An unadulterated flat tax—which Carson may or may not favour—would raise taxes on the poor and reduce them on the rich. That would almost certainly decrease net national happiness. The reason is obvious: People who are just barely getting by, living from paycheck to paycheck, would find it very hard to pay more in taxes than they do now. People who make a lot of money have far more breathing room," he said.

Tax Foundation economist Kyle Pomerleau, also raised the possibility that Carson may not have fully developed his tax plan yet.