John Sudworth
North America Correspondent, reporting from the convention

Kamala Harris goes into this convention buoyed by some encouraging opinion polling and she’ll be given a rapturous reception by delegates.

The first big keynote address will be given by President Joe Biden, a potentially bittersweet moment for him as he hands the baton to a candidate whose relative youth was, in the end, the one quality he could do nothing to match.

But although Harris has closed the gap with Donald Trump, the polls remain extremely close and she faces challenges from Republicans, attacking her past liberal policy positions on migration and policing, and some in her own base protesting on the streets of Chicago over US support for Israel’s war in Gaza.

The speeches have kicked off and you can watch them as they happen with our live coverage of the Democratic National Convention at the top of this page.

Just hit the "watch live" button.

We will continue to bring you text updates, photos and analysis as well, so stick with us.

Bernd Debusmann Jr
Reporting from the convention

We just heard from Rich Logis, a former Republican MAGA voter who has now thrown his support behind Kamala Harris.

By inviting him on stage, Democrats likely hope to hammer home a point that they have been attempting to make for weeks now: that, in their eyes, Harris is more electable than Biden was. Their aim is to sway voters that may once have voted for Trump.

While Harris holds leads in several national polls, whether she has been able to reach MAGA Republicans - a group that forms Trump's base - remains an open question.

A Pew poll released just five days ago found that, overall, Republican views of Harris remain overwhelmingly negative, with 89% holding an unfavourable impression.

Bernd Debusmann Jr
Reporting from the convention

The most visceral reactions from the crowd has so far been the loud boos for Donald Trump.

Just a few moments ago, the rapidly growing crowd was shown a series of video clips of Donald Trump discussing Covid, which early on in the pandemic he said would "disappear".

"Donald Trump failed us," Illinois congresswoman Lauren Underwood said. "Joe Biden and Kamala Harris said help is on the way."

"We can never let him be our president again," she added to applause from the crowd.

So far tonight, contrasting the Harris-Walz campaigns with Trump's is the major theme.

Bernd Debusmann Jr
Reporting from the convention

Image source, Reuters

Just a little while ago, we caught a glimpse of Jesse Jackson, a prominent civil rights leader.

He's in a wheelchair now - and did not say anything while on stage, flanked on one side by Al Sharpton, another civil rights icon.

He did, however, get a standing ovation from the crowd.

Among civil rights advocates, he - and Sharpton - are extremely influential.

Their presence in stage is sign that the Harris-Walz campaign hopes to contrast itself with Trump's campaign.

Both men have had an extremely adversarial relationship with Trump over the years.

Bernd Debusmann Jr
Reporting from the convention

I'm back on the floor of the convention, which is starting to fill up quickly as state delegates stream in.

We're still a few hours off from President Biden and many of the more prominent speakers of the night, but the excitement in the room is palpable.

Delegates are cheering, even as they discuss otherwise dry matters about rules and orders of business.

"Let's get going!," someone just yelled.

Image source, Brandon Drenon / BBC

Mohamed Mohamed, a South Dakota delegate, is reflective of just the type of voter that Democrats are hoping will fall into the fold.

For months, one of the main headlines ailing Joe Biden's campaign was the growing apathy toward Democrats from young and black voters, particularly young black men.

But Mohamed, 21, now keeps thinking about the "vibe shift" he says has happened since Kamala Harris has taken over as the party's nominee.

As a delegate, Mohamed's allegiance to the Democrats was steadfast, even with Biden at the top of the ticket, but he says now people in his demographic more broadly are "very excited about the entire campaign".

"For Gen Z and young black voters, I think [Harris] is going to overwhelmingly win it."

"It's just such a historic moment."

Mike Wendling
Reporting from Chicago

Protesters are now returning to Union Park after marching near the convention site.

We’ve seen reports that an outer security fence was knocked down and that a group of protesters rushed through, chanting “Whose streets? Our streets!”

Local media is reporting that police swiftly gained control and moved protesters out of the security zone, and that several arrests were made.

The march has otherwise been orderly so far, with most of the protesters sticking to the agreed-upon route.

Caitlin Wilson
Reporting from the convention

Official programming is getting under way here at the United Center, though the seats inside the arena are far from full and there are still delegates and Democratic lawmakers milling around outside the main event space.

So far, we've heard an acknowledgement of the Native American land that Chicago sits on, the US pledge of allegiance and the US national anthem.

Phil McCausland
Reporting from the convention

Cedric Richmond, an adviser to the Democratic National Committee, told reporters that Monday’s celebration of Biden’s accomplishments is key to re-engaging the voters who cast their ballots for the Democratic ticket in 2020.

The former Louisiana congressman who served as a White House adviser to President Biden declined to give away too much about Biden’s speech tonight, but he said that the president would remind voters about what this White House has accomplished.

“The President tonight (will) talk about the successes of the Biden-Harris administration, and I think it's important for him to answer those age old questions of: what have you done for me lately? Why bother to actually go out and vote?” he said.

“Biden has to remind them of the successes of the Biden-Harris agenda,” he added.

BBC's chief US presenter Caitríona Perry spoke with Philadelphia lawmaker Brendan Boyle earlier today, and they discussed what exactly we might see when President Biden walks on the stage.

Boyle says it's going to be an "emotional night".

Phil McCausland
Reporting from the convention

If you've listened to Kamala Harris, Tim Walz or Democrats talking about their ticket for president, you'll have heard them use the word "joy" - or some variation of it - quite a bit.

It's been a word readily used by Democrats to emphasise the good vibes of their nascent campaign - a, perhaps, gentler message than President Biden's concern that Trump posed "a threat to democracy" or the critical messaging used by the Republican campaign.

That hasn't changed at the DNC.

As Cedric Richmond, a former Biden administration adviser, told reporters here earlier: "We're ready to answer the divisive, backwards vision of Donald Trump with a positive, joyful vision for the future".

Walz himself invoked "joy" to a number of rooms filled with delegates this morning, and several other politicians have used the word in speeches about the vice-president.

It's a message that could do well with voters who have been exhausted by the US's harsh political messaging over the past eight years. And with a shortened campaign season - there are fewer than 80 days until election day - perhaps all the Harris-Walz campaign will need are those good vibes.

But, at some point, it could become difficult to ignore the growing drum beat for concrete policy platforms and press access to the vice-president.

Rebecca Hartmann
Reporting from the convention

Final preparations are under way here ahead of the opening of the convention, which is expected to start shortly.

Earlier, a choir practiced the national anthem and two children recited the pledge of allegiance on stage.

President Biden and his wife Dr Jill Biden also appeared briefly on stage, walking through ahead of their separate speeches this evening.

Though Kamala Harris has been riding a wave of momentum in recent weeks following her entrance into the presidential campaign - and Democrats surely hope this convention will give her another polling bump - the 2024 race is still a tight one.

The latest poll from the BBC's US partner CBS , externalsuggests Harris has a slight advantage among likely voters nationally, with 51 percent saying they'll vote for the vice president and 48 percent saying they'll vote for Donald Trump.

But US elections are hardest fought in a handful of so-called swing states, including Michigan, Wisconsin, Pennsylvania and a few others.

Support for Harris and Trump appears to be evenly split in those states, according to the CBS poll, which was published Sunday and data was gathered from 14-16 August.

In those battleground states, 50 percent of likely voters say they support Harris, and 50 percent say they support Trump.

Image source, Getty Images

It's about 20 minutes until speeches start at the Democratic National Convention in Chicago, where President Joe Biden will be today's headline. While we wait for that, let's check in with what Republican presidential nominee Donald Trump got up to today.

Trump was in the battleground state of Pennsylvania, where he held an event on a factory floor.

He spoke with media there, and repeatedly attacked his political opponent Kamala Harris, mispronouncing her name multiple times.

"Kamala Harris is an economy wrecker," Trump said. "Our country will be destroyed if she gets in."

Trump heads to Michigan on Tuesday for more campaign stops.

Brandon Drenon
Reporting from the convention

Image source, Brandon Drenon / BBC

Texas delegate Luciano Garza walked into the United Center wearing layers of beaded red and blue necklaces and a sparkling smile.

As he made his way toward his seat - hours before the first speaker was slated to start - he said he was "full of joy".

Moving Kamala Harris to the top of the Democratic ticket has brought "a burst of energy and optimism" to Texas voters, he says.

"With no disrespect, [Joe Biden] was dragging us down and dragging us down down ballot"

"Then all of a sudden, we have joy," he says.

His sentiment reflects the shift in momentum that has occurred since President Biden stepped aside; supported by some recent polls that show Harris making up ground and moving marginally ahead of Donald Trump.

Mike Wendling
Reporting from Chicago

Image source, Mike Wendling / BBC

The protest is slow, loud and peaceful as it winds its way through mostly residential streets around the United Center.

The marchers are sticking to the agreed route around the DNC site and police are tracking the protest using bikes, vans and helicopters.

Image source, Mike Wendling / BBC

Bernd Debusmann Jr
Reporting from the convention

Speaking to a small crowd of reporters and delegates, Michigan Senator Gary Peters defended his party's handling of increasing calls for Joe Biden to step aside as presidential nominee, saying that it was unclear what the "process" would have looked like if Biden had not wanted to leave the race.

Peters praised Biden's decision as giving the Democrats new momentum as the US heads to the November election.

"Imagine that, a president that puts himself second to what's good for the country," he says. "There's another recent president that wouldn't apply to."

Peters says he has not spoken to Biden since he withdrew from the race.

Despite his withdrawal, Peters said that the sitting president will form an integral part of the Democrat's efforts in the 78 days that remain in this election.

"Clearly, having the president out there talking to people is going to be important, talking about the accomplishments of his administration," he says.

Bernd Debusmann Jr
Reporting from the conventiuon

Image source, Bernd Debusmann Jr / BBC

Among those who have spoken so far at this year's Democratic National Convention is Michigan Senator Gary Peters, now the chair of the Democratic Senatorial Campaign Committee.

Like other lawmakers we've spoken to today, Peters is quick to point out the "enthusiasm" he believes has been injected in the Democratic campaign since Kamala Harris became the candidate.

Michigan is considered a key "battleground" state in which the election promises to be extremely competitive.

"Folks just wanted a fresh face. Somebody new. New ideas, younger," he says. "She checks all those boxes."

Peters - who served alongside Harris as a Senator - says that he spoke to Harris within two hours of Biden's announcement that he would withdraw from the race.

Asked what Harris needs to do to emerge victorious in Michigan, Peters says she must "be authentic" to win over sceptical voters.

"People have to see who she is," he says. "People like to know folks are speaking from the heart and are given a straight story. She needs to show how she cares."

Asked about the battle to control the Senate since Biden withdrew, Peters said "things have gotten better" for the party's candidates.

"We just saw enthusiasm for the race increase, and you're seeing it in volunteers, and in our fundraising," he says.