Republicans in the House of Representatives and Senate are pushing President Donald Trump-supported tax reform legislation through the committees with the help of influential donors.
The legislation would simplify the tax code, increase taxes on businesses and increase the national debt by reducing the size of the federal government.
It would also provide a big boost to the economy, which is already in the midst of a global recession.
The House and Senate committees are expected to take up the legislation this week, after weeks of meetings.
The bill is being sponsored by House Ways and Means Committee Chairman Kevin Brady, R-Texas, and Senate Finance Committee Chairman Orrin Hatch, R -Utah.
Republicans in both chambers of Congress have been pushing the legislation for months, and the two committees have been meeting every day.
The plan would end the Bush-era tax cuts for corporations and individuals.
It also would eliminate a number of tax breaks that many lawmakers said benefited the wealthy and favored the wealthy.
The Senate Finance committee, however, has pushed back against the proposal, arguing it does not go far enough.
The nonpartisan Tax Policy Center estimated that the GOP plan would add $1.2 trillion to the debt over 10 years.
Democrats, meanwhile, have repeatedly slammed the tax plan, saying it does little to help the middle class and that it hurts the economy.
The tax plan also would provide a massive tax break to corporations that pay little or no federal income taxes.
That includes $1 trillion for the wealthy, according to the Center for Budget and Policy Priorities.
The Republican plan would also allow corporations to write off their tax liabilities to their shareholders, which the group estimates would increase their bottom line.
The Congressional Budget Office has estimated that corporations would end up with about $6 trillion more in tax bills, though the CBO has not said how much of that money would be paid by companies.