Treasury Secretary Steve Mnuchin promised the “largest tax reform in the history of our country” on Wednesday as the White House and congressional Republicans gear up for a major overhaul.

But while their plans emphasize large tax cuts for corporations and more modest ones for individuals, some Democrats are promoting something far more radical: the end of the tax return.

Led by Massachusetts Sen. Elizabeth Warren, the Democratic effort is something many taxpayers might cheer, but tax preparation companies are working hard to oppose that proposal.

In countries where return-free filing exists, the government sends taxpayers returns filled out with information it has collected. If a return looks right, the taxpayer signs it and sends it back. If it doesn’t, the taxpayer can contest discrepancies, or send in their own return.

The latest effort for return-free tax filing began shortly before Tax Day this month, when Warren and 10 other co-sponsors announced plans to reintroduce the Tax Filing Simplification Act, legislation that the Massachusetts Democrat originally introduced last Congress.