The House on Tuesday approved a massive tax overhaul that would usher in steep rate cuts for American companies, double the deduction millions of families claim on their annual returns and make a host of other changes as part of the biggest rewrite of the tax code since the Reagan administration.

The bill passed on a 227-203 vote, with 12 Republicans defecting to join Democrats in opposition. The Senate started debate shortly afterward, with a vote expected overnight.

Due to a parliamentary glitch, however, the House will likely have to vote one last time before the legislation can be signed. Three provisions in the House version violated Senate budget rules, so they will have to be stripped before a final House vote on Wednesday.

Ahead of the vote, Senate Majority Leader Mitch McConnell predicted in an interview on Fox News that the bill would be approved by both houses and President Trump would sign it into law soon.

"It's going to pass and he will sign it in all likelihood this week," McConnell said Tuesday evening on "Special Report with Bret Baier."

The $1.5 trillion package, presuming it clears Congress in the end, would hand Trump his first major legislative victory just days before year’s end and the congressional recess.

“Today, we are giving the people of this country their money back,” House Speaker Paul Ryan, R-Wis., declared Tuesday on the House floor.

At an earlier news conference, Ryan said that “families at every income level get a tax cut,” vowing that a family of four making the median income would see a tax cut worth over $2,000.

WHAT THE TAX BILL MEANS FOR YOU

'Today, we are giving the people of this country their money back.' — House Speaker Paul Ryan

“This is real relief, and people are going to see this in their paychecks before too long,” Ryan said. He added that "this is the greatest example of a promise being made and a promise being kept.”

Democrats sustained their vocal opposition to the bill – they’ve dubbed it a “scam” benefiting the wealthy – into the final moments before the vote. And protesters were escorted out after shouting out during Ryan's floor speech, “You’re lying!”

Ryan, Trump and other supporters have countered the criticism by claiming the bill would unleash economic growth. The speaker led a round of applause on the House floor minutes before the vote, while thanking “architect” Rep. Kevin Brady, R-Texas, chairman of the Ways and Means Committee.

The floor action comes after GOP leaders worked to win support from the last remaining holdouts on the Senate side. Sens. Marco Rubio of Florida and Bob Corker of Tennessee backed the bill last week, while Susan Collins of Maine and Mike Lee of Utah endorsed it late Monday.

Barring any unexpected reversals, the bill is expected to narrowly pass the Senate in a matter of hours.

Passage would give Trump a major victory on the domestic front, after repeated attempts to overhaul Obamacare failed in the face of internal Republican divisions and unified Democratic opposition. The tax bill does include one major rollback of the Affordable Care Act, repealing the individual mandate requiring Americans to buy health insurance.

The changes to the tax system are more sweeping.

The final bill – a combination of previously passed House and Senate legislation – would slash the corporate tax rate from 35 percent to 21 percent. It would double the standard deduction used by about two-thirds of U.S. households, to $24,000 for married couples. And the $1,000-per-child tax credit would double to $2,000, with up to $1,400 available in IRS refunds for families who owe little or no taxes.

The corporate tax cut would be permanent, while the tax cuts for individuals would expire in 2026.

The Trump administration presumes that the doubling of the standard deduction would lead to even more families claiming it.

But those who itemize would lose some deductions.

The bill would set a new $10,000 cap on the deduction that millions use in connection with state and local income, property and sales taxes. The cap remains in the final bill. It also would cap the mortgage interest deduction at $750,000, down from $1 million.

At the same time, the bill would lower the top rate for individual and married filers from 39.6 percent to 37 percent. Further, it would set a deduction for “pass-through” business income at 20 percent. And it would curb the so-called estate tax.

These provisions and others fueled Democratic complaints that the legislation was skewed to favor corporations and the wealthy – while expanding the deficit.

On the House floor, Rep. Terri Sewell, D-Ala., mocked Republicans who say passage of the bill would be a Christmas gift to the American people.

“I have never seen such intellectual dishonesty,” Sewell said Tuesday afternoon. “It’s more like the Grinch that stole Christmas.”

Sewell said recent elections, where Democrats won races in New Jersey, Virginia and Alabama, show that voters don’t want the tax bill to move forward.

“But here we are, watching the fiscal hawks of the Republican Party blow through every red light on the way off the cliff, adding $1.5 trillion to the deficit,” she said.

House Minority Leader Nancy Pelosi, D-Calif., spoke in front of a giant sign that read, “#GOPTAXSCAM.”

The bill would bring average initial tax cuts for Americans across all income lines, but by 2027, it would boost average levies for everyone earning up to $75,000, which includes most taxpayers, Congress' nonpartisan tax analysts estimated Monday.

A separate study by the Tax Policy Center, a private nonpartisan group, found that individual taxes would be reduced on average next year by $1,600. That ranged, on average, from $60 for people earning below $25,000 to $7,640 for those making above $149,000. Those in the top 1 percent, earning over $733,000, would see average tax cuts of $51,140.

Fox News’ Alex Pappas and The Associated Press contributed to this report.