Senate Democrats unveiled a proposal Wednesday to significantly expand tax credits for children and low-income households — and provide fresh ammunition for attacking President Donald Trump's tax cuts.

The effort is led by Sen. Sherrod Brown of Ohio, who had toyed with launching a 2020 presidential campaign but decided to focus on working-class issues as a lawmaker. The new bill would roughly quadruple the earned income tax credit for childless workers, increase the credit for households with children and create a new benefit for children under age 6.

The proposal has the backing of Dick Durbin of Illinois, the second-ranked Democrat in the Senate; Ron Wyden of Oregon, the ranking member of the Senate Finance Committee; and Michael Bennet of Colorado, who is planning to run for president.

Under the plan, known as the Working Families Tax Relief:

The tax credit for low-income households without children would jump from a maximum of $530 to $2,070. It would also expand the eligible ages to 19 to 67 from the current 25 to 64.

That credit would rise by roughly 25% for families with children.

Households could receive a one-time, interest-free advance on those credits worth up to $500.

Families with young children could also claim a new tax credit of up to $3,000.

The senators argue that the plan would have broad ramifications, especially for poor families. They estimate it would lift 7 million people out of poverty, including 3 million children, and increase incomes for 46 million households. "As Americans are filing their taxes, more and more people are seeing the Trump tax scam for what it was — a handout to millionaires and billionaires at the expense of working people and families," the lawmakers said in a statement.

The plan does not include corresponding tax increases on the wealthy or for raising the corporate tax rate — measures that have gained traction among progressives and have been embraced by several Democratic presidential candidates. The senators also did not provide an estimate of how much the proposal would cost.

Republicans hold a 53-47 advantage in the Senate, making it unlikely that Democrats will pass the measure any time soon. The bill has 44 co-sponsors in the Democratic caucus. The three holdouts are Joe Manchin of West Virginia, Dianne Feinstein of California and Kyrsten Sinema of Arizona.

Still, the bill gives Democrats a fresh political tool to hammer the GOP and Trump with the 2020 elections on the horizon. The measure is intended to be a counterpoint to the sweeping overhaul of the tax code that Trump signed at the end of 2017. Democrats have criticized the law as primarily benefiting corporations and the wealthy and appear to be winning the messaging battle. According to the latest NBC/Wall Street Journal poll, only 17% of voters believe they will receive a tax cut as a result of those changes. More than a quarter said their taxes would go up.

Democrats have pressed their advantage with a slew of proposals targeted at reducing taxes for working families and expanding the social safety net. Brown has long pushed to expand the low-income tax credit and give workers early access to their refunds, but this latest bill goes further.

It also echoes a proposal from Sen. Kamala Harris of California, a Democratic presidential hopeful. Her bill, the Lift Act, would provide a refundable tax credit worth up to $6,000 for households — with or without children — and allow them to receive payments in an annual lump sum or monthly installments.

An aide to Brown said the price tag — and how to to pay for it — would be part of the debate over the bill. Democrats also intend to highlight that the Republicans' tax cuts will cost $1.5 trillion over a decade and has contributed to higher deficits over the past year.