Americans were taken back four years as former President Barack Obama made his debut appearance on the 2020 trail in a fiery attack on Donald Trump.

Obama pulled no punches as he criticised Trump's response to the  coronavirus  pandemic, saying his administration left the White House a "pandemic playbook" that has been ignored.

Elsewhere fake emails sent to Democrat registered voters threatening them to vote Republican came from Iran, the FBI has claimed though provided no evidence.

The President's 'fixer' Rudy Giuliani labelled his opponents "scum" after he was 'caught out' by Sacha Baron Cohen ahead of the actor's upcoming Borat sequel.

Meanwhile, Joe Biden broke hearts in a resurfaced clip and Trump left Twitter baffled after sharing photos of his healthcare 'big book' in which pages appeared to be blank.

Aside from a closed-press Trump supporter roundtable in Nashville, both campaigns now have clear schedules until 2am tomorrow UK time for the Final Presidential TV Debate.

Here's all you need to know.

Iran behind email threats to US election, says FBI

Director of National Intelligence John Ratcliffe

Threatening emails sent to Democrat registered voters originated in Iran and were intended to intimidate as well as make Trump look bad, the FBI said.

Top intelligence officials, including Director of National Intelligence John Ratcliffe, held a hastily arranged press conference, also announcing some voter registration data had been obtained by Russia and Iran.

And they said a rash of threatening emails, apparently from far-right group The Proud Boys, were in fact the work of Iran.

It's unclear whether the registration data was publicly available or hacked - and the officials did not take questions or provide any evidence.

Biden comforting shooting victim's son goes viral

Joe Biden hugging the son of a school shooting victim

A clip of Biden comforting the son of school shooting victim Chris Hixon in 2018 has re-emerged online - and touched thousands of viewers.

The footage shows the former Vice President attending a 2018 memorial service for the Marjory Stoneman Douglas School athletic director.

Hixon was one of 17 people murdered in a shooting spree at the school in Parkland, Florida, after trying to disarm the gunman.

In the heartbreaking video, Biden asks to speak to Mr Hixon's family, telling the victim's distraught son Corey: "It's going to be okay. We're going to be okay. I promise."

Obama rips into Trump in electric campaign speech

Barack Obama tore into Trump in his feisty first intervention of the 2020 Presidential election, attacking his successor over his approach to Covid-19 and healthcare, his love of conspiracy theories and the revelation that he has a secret Chinese bank account.

And he urged Americans to listen to the "better angels of our nature" - voting to "leave no doubt about what this country that we love stands for".

He said President Trump wanted to "take full credit" for the economy he inherited, but zero blame for the pandemic he ignored.

"Making stuff up doesn't make people's lives better. You've got to have a plan. You've got to put in the work," he added.

Trump lawyer claims he was 'tucking shirt in'

Rudy Giuliani with Trump

Former New York Mayor and Trump's current 'fixer' Rudy Giuliani says he was merely tucking in his shirt while stretched out on a bed in a hotel room with a young woman posing as a reporter in the new Borat movie.

Giuliani says the secretly filmed footage was the result of a "hit job", and that there will be five or six more of them to come, because his political opponents are "scum."

In a radio interview, he said his shirt came untucked while he removed electrical equipment and he was leaning back on the hotel bed as he put it back, but is adamant "my clothes were entirely on".

"I assure you that’s all I was doing," he added.

Trump hands TV host 'book with blank pages'

Trump appeared to give 60 Minutes journalist Lesley Stahl a giant book with blank pages as proof of his healthcare plans.

The President tweeted a series of pictures of Press Secretary Kayleigh McEnany presenting the host with a large tome, which he said included "some of the many things we've done for healthcare."

Further inspection of the final photo in the set appears to show at least some of the pages of the book are entirely blank.

The exchange followed claims that the interview - to be aired on Sunday - descended into drama, with the President ending the conversation early and refusing to carry on with a later 'walk and talk' alongside Vice President Mike Pence.