The US Senate on Wednesday approved the final version of the first overhaul of the US tax code in more than three decades, handing President Donald Trump and congressional Republicans their most significant legislative victory of 2017.

The bill passed the Senate 51 to 48 with no Democrats backing the bill while all present Republicans voted for it. The final result was announced by Vice President Mike Pence who presided over the vote.

Earlier, the House passed the bill on Tuesday but technical changes were made to it in the Senate. The bill will go back to the House on Wednesday for a re-vote where it is expected to pass again, the New York Times reported.

It will then head to the President’s desk for his signature before Christmas, making good on the Republican Party’s promise to enact tax relief by the end of the year.

The $1.5 trillion tax bill will have broad effects on the economy, making deep and lasting cuts to corporate taxes. It will also lower income tax bills in 2018 for the vast majority of households, though the wealthy would see far more relief than the middle class and working poor.

The plan would revise nearly every part of the tax system by lowering income tax rates at all levels and restructuring deductions. And it extends beyond taxes and into healthcare by scrapping a central part of the Affordable Care Act.

Trump acknowledged the Senate’s vote in a tweet: “The US Senate just passed the biggest in history Tax Cut and Reform Bill. Terrible Individual Mandate (ObamaCare) Repealed.”

The approval of the bill in the House and Senate came over the objections of Democrats, who accused Republicans of giving a gift to corporations and the wealthy.

At around midnight, Senate Minority Leader Chuck Schumer made his final pitch to his colleagues to vote against the tax bill. He said that “this is some bill for the middle class”, noting the heftiest provisions will help corporations.

Representative Nancy Pelosi, the House Democratic leader, called the tax bill a scam, saying it “is simply theft – monumental”.

Under the final tax bill, the corporate tax rate would fall to 21 per cent, from the current 35 per cent, a move that Republicans bet will increase economic growth, create jobs and raise wages.

Individuals would also see tax cuts, including a top rate of 37 per cent, down from 39.6 per cent.

The size of inheritances shielded from estate taxation would double, to $22 million for married couples, and owners of pass-through businesses, whose profits are taxed through the individual code, would be able to deduct 20 per cent of their business income.

But the individual tax cuts would expire after 2025, a step that Republicans took to comply with budget rules.

The tax changes will affect businesses and individuals unevenly. The bill strikes at a core component of the Affordable Care Act, eliminating the requirement that most people have health coverage or pay a penalty, a move that the Congressional Budget Office projects will increase premiums for people who buy insurance.

It will also open the Arctic National Wildlife Refuge in Alaska to oil and gas drilling, a defeat for environmentalists who have fought against such action for decades.