Barack Obama tore into Donald Trump in his feisty first intervention of the 2020 Presidential election.

He attacked 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 joked: "Can you imagine if I had a secret Chinese bank account while I was running for reelection?

"Fox News would have called me Beijing Barry."

The former US President joined Joe Biden's campaign trail today for the first time, holding a drive-in rally in Pennsylvania.

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

"But you know what? The job doesn't work that way. Tweeting at the television doesn't fix things. 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."

And he pulled no punches as he blasted Trump's response to the coronavirus pandemic.

"We literally left this White House a pandemic playbook that would have shown them how to respond before the virus reached our shores," he said.

"They probably used it to, I don't know, prop up a wobbly table somewhere.”

Obama's appearance fills a gap left by Biden, who has stayed at home in Delaware since Monday for meetings and preparation ahead of this week's debate with Trump in Nashville, Tennessee.

He said the President's plan to gut the Affordable Care Act - Obamacare, one of the Obama administration's biggest achievements - was "shameful."

And becoming audibly angry, the former President said: "I can tell you this. Joe Biden would never call the men and women of our military suckers or losers.

"Who does that? These heroes are somebody's children. Somebody's spouse, or mom.

"He understands that. And he's going to restore our standing in the world, because he understands that America's true strength is in setting an example that the world wants to follow."

He suggested Biden and Harris would make everyday life in America less contentious.

"You're not going to have to argue about them every day," he said. "It just won't be so exhausting. You might be able to have a thanksgiving dinner without having an argument.

"You'll be able to go about your lives knowing the President of the United States isn't going to retweet conspiracy theories about secret cabals running the world, or that Navy SEALS didn't really kill Bin Laden."

Becoming exasperated, he said: "Think about that. The President of the United States retweeted that.

"Wha....what?"

He said insulting people you don't agree with and threatening them with jail is "not normal behaviour."

He urged them not to accept it from the President any more than it would be accepted by a college principle or a family member - "apart from maybe a crazy uncle, because he's...you know."

Mr Obama pleaded: "Why would we accept this from the President of the United States? And why are folks making excuses for that?

"'Oh well, that's just him'. No its..." he sighed. "No. There are consequences to these actions.

"They embolden other people to be cruel and divisive and racist, and it frays the fabric of our society and it affects how our children see things."

"We've got to vote, like never before, and leave no doubt," the former President said as he wound up.

"And if we pour all our efforts into these 13 days, if we vote up and down the ticket like never before, then we will not only elect Joe Biden and Kamala Harris.

"We will leave no doubt about what this country that we love stands for. We will leave no doubt over who we are as a people, and the values and ideals that we embrace.

"What Lincoln called the 'better angels of our nature'. Those are still in us. We see them operating every single day. We see them in neighbourhoods. We see them in synagogues and mosques and churches and temples.

"We see them in people helping out a neighbour. We see them in our own families.

"We see that what is best in us is still there. But we've got to give it voice, and we've got to do it now."

As he ended his speech to the drive in audience, he urged supporters to "honk if you're fired up, honk if you're ready to go."