The tax overhaul, which would be the largest change to the US tax system since the 1980s, was approved by Senates on Saturday in a 51-49 vote following a series of last minute changes to the bill.

The tax plan would see a cut in corporate tax but the Senate committee has warned it could add more than $1trn to the budget deficit over years.

President Donald Trump, who has called the plan a “big, beautiful Christmas present”, praised the Senate for passing the “tremendous tax reform” and said “people are going to be very, very happy” as the US is “one step closer to delivering massive tax cuts for working families”.

The bill included a cut of corporate tax from 35% to 20%, while future foreign profits of US-based firms would be mainly exempt from tax. The last minute changed included a $10,000 property tax deduction.

Democrats have complained the tax bill would only benefit the wealthy and big businesses, leaving the poor behind.

The Democrats also criticised the bill for being poorly drafted. Senate Democratic leader Chuck Schumer said: “The Republicans have managed to take a bad bill and make it worse.

“Under the cover of darkness and with the aid of haste, a flurry of last minute changes will stuff even more money into the pockets of the wealthy and the biggest corporations.”

As Republicans hold a 52-48 Senate majority, Democrats were unable to block the vote despite voting against the bill.

The Senate will now merge its legislation with that passed last month by the House of Representatives before it can be signed into law by Trump.

Trump said: “Something beautiful is going to come out of that mixer.”

The US president outlined the major tax cuts, which he described as “the largest tax cut in [the] country’s history”, in September.