Watch a clip of Mitt Romney addressing the Senate earlier, explaining his decision to vote to remove Trump from office.

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Mitt Romney may well end up being the only Republican senator out of 53 to vote to convict Trump today.

The Utah senator, who was the 2012 Republican presidential candidate, has already swum against the tide during the trial. Last week, he and Maine senator Susan Collins were the only two Republicans to vote to call witnesses in the trial. Allowing witnesses could have opened the door for testimony potentially harmful to Trump's defence.

In the end, the majority of Republicans outnumbered them, but Romney - who is almost as establishment a Republican there is - became a rare voice of dissent. He said it was "critical for the facts to come out".

It came at a cost - he was almost immediately disinvited from CPAC, the main annual conservative conference, and become a target for Republican scorn (the president tweeted clips of Romney's 2012 defeat and Donald Trump Jr called him "my favourite Democrat".)

Romney's not facing re-election until 2024, so any comeback at his decision won't be felt at the polling booth any time soon.

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A Gallup poll, external yesterday gave Trump his highest approval rating yet at 49% - and showed the highest party polarisation on record.

The poll also noted his approval among Republicans was 94% and 42% among independents. Democratic approval, meanwhile, was at 7%.

But half of registered voters polled told Gallup Trump deserves to be re-elected.

The high ratings could be in part due to high optimism about the economy. A Gallup poll today, external found 59% of Americans say they are better off financially now than last year. And three in four expect to be better a year from now, the highest polled by Gallup since 1977.

Romney just gave an interview to Fox News, moments after his bombshell Senate speech, announcing he would vote against the president. Fox hose Chris Wallace told him, "This is war."

Top House Democrat Jerry Nadler, one of the impeachment managers during the trial, told reporters earlier today that the lower chamber may widen a House probe against Trump even if he is acquitted.

Nadler said the House was "likely" to subpoena former National Security Adviser John Bolton for testimony.

Bolton caused a huge stir during the trial when reports said that his forthcoming directly linked Trump to the alleged Ukraine pressure campaign - the only first-hand account to tie Trump directly to the scheme.

If Bolton were to testify, Nadler said, "we're talking about everything”.

Moments after Mitt Romney said he would vote to convict Trump, the White House cancelled a "pool spray" photo-op event with the Venezuelan opposition leader Juan Guaidó.

It was unclear if Romney's announcement was the reason for the cancellation

Guaidó attended last night's State of the Union speech, at the invitation of President Trump.

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Senator Doug Jones, a moderate Democrat from Alabama, has said he'll vote to convict.

He was seen as a possible Democratic defector as his state leans conservative. "I have reluctantly concluded that the evidence is sufficient to convict the President for both abuse of power and obstruction of Congress," he said in a statement.

"To do otherwise risks guaranteeing that no future whistleblower or witness will ever come forward and no future President - Democrat or Republican - will be subject to Congressional oversight as mandated by the Constitution.

"This has been a divisive time for our country, but I think it has nonetheless been an important constitutional process for us to follow. As this chapter of history draws to a close, one thing is clear: our country deserves better than this."

Jones is up for re-election this year after having won his seat in a special election at the end of 2017, and it’s likely he won’t keep it.

• Who is Doug Jones?

Mitt Romney just finished addressing the Senate chamber, giving his reasons for voting against his party and the president.

"I'm aware that there are people in my party in my state who strenuously disapprove of my decision," he said.

"I'm sure I'll hear abuse from the president and his supporters," he added, saying that his decision was made after much praying.

“I believe that attempting to corrupt an election to maintain power is about as egregious an assault on the Constitution as can be made. And for that reason, it is a high crime and misdemeanor and I have no choice under the oath that I took but to express that conclusion.

"We've come to different conclusion fellow senators, but I trust we have all followed the dictates of our conscious".

He concluded: "I will only be one name among many - nor more, no less - to future Americans who will note merely I was among those that determined what president did was wrong grievously wrong."

"I will tell my children I did my duty to the best of my ability."

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Utah Senator Mitt Romney has just announced he will vote to convict Trump.

He is so far the only Republican who has said he will vote for Trump's removal.

"I think the case was made," he told reporters as he left his Senate office.

Welcome back to our live coverage of the Trump impeachment trial.

In a few hours, Senators will finally vote on whether or not he is removed from office.

There is virtually no chance he will be convicted - a two thirds majority of senators is needed for a conviction and the president's Republican Party controls the Senate 53-47.

Trump is the third president in US history to be impeached - after Andrew Johnson and Bill Clinton - but none has ever been convicted and removed from office.

Senators are due to vote at around 16:00 local time (21:00 GMT) on the two charges against Trump - abuse of power and obstruction of Congress.

Image source, AFP

We're wrapping up our live coverage of Friday's impeachment trial. Here are the main points you need to know.

• Senators have narrowly rejected a motion to call new witnesses to the Senate impeachment trial of Donald Trump.
• Democrats had hoped that four moderate Republicans would defect and join them in voting for witnesses.

• However, Senator Lamar Alexander of Tennessee said late on Thursday that while the president's actions were "inappropriate", they were not impeachable offenses.
• On Friday, Senator Lisa Murkowski also said she would vote against calling witnesses.
• In the end, the motion failed 51-49, with Republicans Mitt Romney and Susan Collins crossing party lines.
• A final vote to acquit President Trump is expected for Wednesday.

You can read more in our news story here.

Anthony Zurcher
BBC North America reporter

Donald Trump’s Senate impeachment trial is all but over.

Barring an unforeseen and unexpected blockbuster development, a largely party-line vote will acquit him of the two charges brought by the House of Representatives, which itself approved those articles of impeachment on a nearly party-line vote.

Both sides will soon be left to sift through the political rubble just nine months before a national election that has the entire House, more than a third of the Senate and the presidency itself on the ballot.

According to polls, the nation’s political disposition is much as it was before the impeachment process began. The US is sharply divided along partisan lines. The president’s approval ratings hover in the low to mid-40s, roughly where they’ve been the entirety of his term in office. His re-election chances are dicey but far from slim.

The decision not to seek witnesses – which polls show Americans overwhelming wanted – may be forgotten before long.

Polls don’t tell the whole story, however, and there are other signs that the impeachment proceedings have made an impact.

Three of the four Democratic senators running for president tweeted in the moments after the witnesses vote went against the party.

The trial is keeping the four - Elizabeth Warren, Bernie Sanders, Amy Klobuchar, and Michael Bennet - from their presidential campaigns while their non-senatorial rivals make hay in Iowa, where the caucuses take place on Monday.

Michael Bennet, the Colorado senator who is also running for president, has not yet commented.

Senate Republicans say they have a deal with the Democrats for an acquittal vote on Wednesday.

They say there will be votes on Democratic amendments tonight - which are likely to be rejected - then senators will return on Monday for floor speeches, and hold the final vote on Wednesday.

In the meantime, there's the curtain-raiser event for the 2020 election with the Iowa caucuses on Monday, then Donald Trump's State of the Union address on Tuesday.

Here's a round up of senators' views on the vote today:

• "There will be no fair trial in the Senate. I don't believe that the continuation of this process will change anything." - Lisa Murkowski, Republican
• "Just because actions meet a standard of impeachment does not mean it is in the best interest of the country to remove a President from office." - Marco Rubio, Republican
• "Senate Republicans have once again voted to hide the truth about the President's actions." - Debbie Stabenow, Democrat.

President Donald Trump has reacted to the vote with a short tweet, again repeating that the Democrats had 17 witnesses, while Republicans had none.

The Democrats have argued that it is Mr Trump's Republicans who balked at the appearance of witnesses.

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Senate majority leader Mitch McConnell has just issued a statement saying it is time to conclude the trial.

The "numerous witnesses" presented to the Senate, and the "28,000-plus pages of documents" were already sufficient to judge the case, he said.

There is no need to re-open the investigation, he adds.

"Never in Senate history has this body paused an impeachment trial to pursue additional witnesses... we have no interest in establishing such a new precedent."

Senators will now "prepare to conclude the trial in the coming days".

Image source, AFP

Senate minority leader Chuck Schumer has condemned the trial, saying there were "no witnesses, no documents".

He told reporters:

• The impeachment trial was "one of the worst tragedies that the senate has ever overcome".
• The Senate did not live up to its responsibilities
• Donald Trump will be acquitted "with no witnesses, no documents" and therefore the acquittal will have "no value"

Testimony from the House investigation had been presented to the Senate, but Democrats were unable to call new witnesses to the Senate trial.

An hour ago, President Donald Trump tweeted - as he has many times before - that the trial is a witch hunt, but he hasn't responded since the vote happened.

The House had invited the president to testify before its investigators, in which case he would have been able to produce witnesses and lawyers, but he declined to do so.