There's been a raucous start to the confirmation hearing of Donald Trump's Supreme Court nominee Brett Kavanaugh.

Mr Kavanaugh has been chosen as the US President's nominee to replace retiring justice Anthony Kennedy.

All US Supreme Court picks are subject to Senate approval.

Today, the Senate Judiciary Committee began the first day of a confirmation hearing that's expected to last several days - with the judge to be quizzed by senators about his record in previous posts.

However, as soon the Senate's Republican chairman Charles Grassley began his opening statement, Democrats objected to last-minute release of a 40,000 page 'document dump' last night.

The huge document trove, related to Mr Kavanaugh's time as a White House counsel during George W Bush's presidency, led to calls by Democrats for the hearing to be adjourned to allow them to fully examine the newly-released documents.

Protesters also heckled senators as the hearing got underway.

A protester holds up a placard and shouts as Supreme Court nominee Brett Kavanaugh during the first day of his confirmation hearings. Picture by: Douliery Olivier/ABACA/ABACA/PA Images

Voicing his support for his party colleague's Richard Blumenthal motion for an adjournment, Democratic Senator Cory Booker argued: "I would venture that not one senator here has had time to read through those 40,000 pages.

"We are continuing to rush through this process - a process that deserves to be scrutinised."

However, following a back-and-forth between members of the committee, the calls were ultimately rejected by Mr Grassley, who claimed there was "absolutely no reason" to delay the hearing.

Activists in the US have been calling for senators to reject Mr Kavanaugh, amid fears the the Republican pick could shift the balance of the country's highest court for decades to come.

However, with a Republican majority in the Senate, it is expected that the US President's nominee will be confirmed.

In excerpts from Mr Kavanaugh's opening remarks released by the White House, the nominee is set to tell senators: "I don’t decide cases based on personal or policy preferences.

"I am not a pro-plaintiff or pro-defendant judge. I am not a pro-prosecution or pro-defense judge. I am a pro-law judge."

Mr Kavanaugh marks President Trump's second Supreme Court pick.

Neil Gorsuch was approved last year, after Republicans controversially refused to allow hearings for Barack Obama's pick - Merrick Garland - for the vacancy in 2016.