With a vote on the biggest tax rewrite in three decades set for tomorrow, Republicans were working to ensure party members were holding the line in favour of the legislation against entrenched Democratic opposition.
The plan was finalised on Friday after Republican Senators Marco Rubio and Bob Corker pledged their support.
Three Republican senators, enough to defeat the measure in a Senate that Trump’s party controls with a slim 52-48 majority, remained uncommitted: Susan Collins, Jeff Flake and Mike Lee.
Passage in Congress would provide Republicans and Trump with their first major victory since he took office in January.
“It’s going to be one of the great Christmas gifts to middle-income people,” Trump told reporters at the White House before he boarded a helicopter for Camp David.
“The Democrats have their sound bite, the standard sound bite before they even know what the bill is all about,” he added.
The proposed package would slash the US corporate tax rate to 21 percent and cut taxes for wealthy Americans.
Under an agreement between the House of Representatives and the Senate, the corporate tax would be 1percentage point higher than the 20 percent rate earlier proposed, but far below the current headline rate of 35 percent, a reduction corporations have sought for years.
Democrats have slammed the plan as a give-away to corporations and the rich that would drive up the federal deficit.
Trump has touted the bill as a middle-class tax cut. Studies from independent analysts have projected corporations and the rich would benefit disproportionately.