The tax plan advanced by Republican presidential candidate Newt Gingrich would have the effect of adding over $1 trillion to the federal deficit in a single year and give the overwhelming share of tax benefits to those at the upper end of the income scale.

A new analysis of Gingrich’s plan, published Tuesday by the Tax Policy Center, found that the top 0.1 percent of taxpayers, those making over $8 million a year, would get an average tax cut of $1.9 million under the plan by 2015. Low-income households, in contrast, would get an average tax cut of $63.

Under Gingrich’s plan, all taxpayers would have a choice between paying taxes under the current Tax Code or under an alternative system based on a 15 percent flat tax. Capital gains, dividends and interest income would not be taxed.

Taxpayers would be able to claim a standard exemption amount of $12,000 for each individual and dependent. The Gingrich plan would also eliminate the standard deduction and most itemized deductions and credits, but would preserve deductions for mortgage interest and charitable contributions along with the Child Tax Credit and Earned Income Tax Credit.  Gingrich’s plan would also repeal the alternative minimum tax.

In terms of business taxes, the plan from the former Speaker of the House would reduce the corporate income tax rate from 35 to 12.5 percent, and permit full expensing of capital expenditures aside from residential rental housing and inventories.

The Tax Policy Center, which operates under the auspices of the Urban Institute and the Brookings Institution think tanks, estimates that the Gingrich plan would lower federal tax liability by $1.28 trillion in 2015 compared with current law, providing roughly a 35 percent cut in total projected revenue. Compared to a current policy baseline, the reduction in liability would be approximately $850 billion in 2015.

The analysis measures the change in tax liabilities against two alternative baselines: current law, which assumes that the 2001-2010 tax cuts all expire in 2013 as scheduled, and current policy, which assumes that the current law is permanent, except for the one-year payroll tax cut. “No one would experience a tax increase from the Gingrich plan under either baseline if they have the option of filing their tax returns under current policy,” said the report.

If taxpayers were required to file under the flat tax option and could not opt to remain under current tax law, revenues in 2015 would fall by about $1.25 trillion relative to a current law baseline and by about $830 billion relative to a current policy baseline.