The US Senate narrowly approved a sweeping tax overhaul early Wednesday, putting President Donald Trump on the brink of his first major legislative triumph nearly a year after he took office.

Hours earlier, Trump's $1.5 trillion deficit-busting tax cuts cleared the House of Representatives, but a rare last-minute snag over parliamentary rules will force the lower chamber to vote on the updated package once again Wednesday.

The deepest rewrite of the US tax code in three decades provides dramatic tax breaks to corporations, and families at all incomes levels will see their income tax drop starting next year, with the largest benefits going to the wealthy.

The Republican legislation passed the Senate along strict party lines, 51 votes to 48, with all Democrats united in opposition.