Image source, Reuters

Tech billionaire Elon Musk has said he will give away $1m (£766,000) a day to a registered voter in the key swing state of Pennsylvania between now and the US election.

The winner will be chosen at random from those who sign a pro-constitution petition by Musk’s campaign group AmericaPAC, which he set up to support Republican nominee Donald Trump's White House return bid.

The first lottery-style cheque was given away to a surprised-looking attendee at a town hall event on Saturday night.

Some have raised questions about the legality of the giveaway, which effectively helps to encourage potential Trump voters to engage in the campaign.

Prominent election law expert Rick Hasen wrote on his personal Election Law Blog, external that he believed Musk's offer was "clearly illegal".

Federal law states anyone who "pays or offers to pay or accepts payment either for registration to vote or for voting" faces a potential $10,000 fine or five year prison sentence.

Though Musk is technically asking participants to sign a form, Hasen questioned the intent behind the strategy.

"Who can sign the petitions? Only registered voters in swing states, which is what makes it illegal," Hasen, a professor at the University of California, Los Angeles (UCLA) law school alleged.

Those who sign the petition - which pledges to support free speech and gun rights - will have to give their contact details, potentially allowing AmericaPAC to contact them about their vote.

Both Musk and AmericaPAC have been approached for comment.

• Read more:Musk to give away $1m per day to Pennsylvania voters

As we've been reporting, Pennsylvania is a key state for both candidates this election cycle - both have already visited multiple times in recent months, and Trump is back this weekend.

The state's Governor Josh Shapiro, a Democrat and top ally of Kamala Harris, sought to play up her record on Sunday as polls suggest his state is an extremely tight race between Harris and Donald Trump.

Shapiro acknowledged to NBC News they were set for another close race in Pennsylvania but he chooses "not to worry about that" and instead campaign across the state.

Shapiro was pointedly asked by Meet the Press host Kristen Welker if he could identify differences between Harris's policies and President Joe Biden's, as voters express frustration with the current administration.

"The contrast I am focused on, Kristen, is between her and Donald Trump," Shapiro said.

He said some Americans have "brain fog" when remembering the Trump administration, which he described as a time of "more chaos, you had less jobs, and you had a whole lot less freedom."

Vice-President Kamala Harris has spent the morning of her 60th birthday addressing parishioners at New Birth Missionary Baptist Church in Stonecrest, Georgia, where she reflected on the Bible story of the Good Samaritan.

She urged churchgoers to "shine the light in moments of darkness", according to the AFP news agency.

"Where we go from here is up to us as Americans and as people of faith," Harris told the congregation.

"What kind of country do we want to live in - a country of chaos, fear and hate, or a country of freedom, compassion and justice?"

Image source, Getty Images

Image source, Getty Images

Image source, Getty Images

Jonathan Csapo
BBC Producer, reporting from Pennsylvania

Image source, BBC / Jonathan Csapo

This is Donald Trump's 23rd visit to Pennsylvania this electoral cycle.

There are still just under seven hours until his town hall begins here in Lancaster.

A large crowd, however, has already formed outside Lancaster's convention centre.

Vendors are already doing brisk business selling Trump merchandise, including stuffed Donald Trump "duckies" and t-shirts.

Marianna Spring
Disinformation and social media correspondent

Noel Drake, a 29-year-old who lives in Utah, said she felt "very bleak" about politics before this year.

During the 2020 presidential election, she felt disillusioned entirely.

But Taylor Swift – and her fans – helped change her mind, she told me.

"With this sense of community that I have established through interacting with other Swifties online, it has really changed the way I interact with politics this election cycle," she said.

After Swift endorsed Democratic nominee Kamala Harris a month ago, Drake started following a fan-led campaign group called "Swifties for Kamala". The group is not officially affiliated with the Harris campaign, but does keep in regular touch with campaign staff.

The BBC has tracked down dozens of voters like Drake, who say posts from Swift and her mega fans on social media have motivated them to go out and vote, or get involved in activism. But just because you’re a fan of Swift doesn’t mean you’re going to vote like her, I learned.

Part of the appeal of a celebrity endorsement – and the political content generated by their fandoms – is that unlike paid-for adverts, this kind of user-generated content feels genuine.

Endorsements can backfire, however, polls show.

Massachusetts resident Bri says she chooses to vote Republican still because "at the end of the day people need to do what’s best for them".

She told me she thinks Swift has such a devoted fan base, she should stay out of politics to be fair to all sides.

• Read more: What impact could Taylor Swift really have on the US election?

Bernd Debusmann Jr
Reporting from Lancaster, Pennsylvania

Both candidates have busy schedules today, with just sixteen days to go until election day.

Donald Trump plans to start his day in Bucks County - which went to Biden in 2020 - where he is going to help work the fryer at a McDonalds and "do everything an employee does".

After that, he'll host a town hall here in Lancaster before headed to Pittsburgh, where he'll take in an NFL game between the Steelers and the New York Jets.

Harris, for her part, will be visiting a Baptist church near Atlanta in Georgia, another key battleground state in which both candidates hope to still win over undecided voters.

While in Georgia, Harris also plans to tape an MSNBC interview with reverend and civil rights figure Al Sharpton.

After that, she'll head up the east coast to Philadelphia, from where she will begin a tour of Pennsylvania, Michigan and Wisconsin on Monday.

Bernd Debusmann Jr
Reporting from Lancaster, Pennsylvania

Image source, BBC / Bernd Debusmann Jr

Good morning from Lancaster, Pennsylvania - where Donald Trump is expected for a town hall later today.

In 2020, this area voted for Trump by a wide margin of 57% to 41% for Joe Biden, about 44,000 votes.

This election, however, promises to be a tight one here in Pennsylvania, meaning that both parties are crisscrossing every corner of the state to woo voters. This is Trump's first time in the area.

We still don't know who will be there with him, although his last town hall was with North Dakota Governor Kristi Noem.

Minnesota Governor Tim Walz has also made appearances here this election cycle.

The town hall tonight takes place at 5pm ET (2200BST). We've just had a look inside the venue and caught a glimpse of the arguments that Trump and his allies will be making tonight.

Many of the digital billboards are focused on economics, such as Trump's vows to end taxes on tips and social security.

Another billboard appears to show men in Afghan traditional clothing burning an American flag along with a caption suggesting that "these will be your neighbours" if Harris wins.

We'll be back in the area speaking to voters a few hours before the town hall begins.

Stay with us for more updates.

Image source, BBC / Bernd Debumasmann Jr

Image source, EPA

Let's turn now to the Sunday morning political programmes, where allies for both campaigns are making their pitches to viewers across the country.

Republican Speaker of the House Mike Johnson has been challenged over Donald Trump's anecdote apparently about late pro-golfer Arnold Palmer's genitalia at a rally on Saturday.

"Is this really the closing message you want voters to hear from Donald Trump?" CNN's Jake Tapper asked Johnson on State of the Union.

Johnson said voters should "put the rhetoric aside [and] look at the record of these two candidates". Johnson said he remained "convinced we're going to win the White House, the Senate and the House" and that people see Trump as a "change agent".

During the rally in Latrobe, Pennsylvania, Trump spoke of Palmer - who was born in the town and is widely considered one of the greatest golfers of all time - recalling what he said were the reactions of other men who took showers alongside the pro-golfer.

"When he took the showers with other pros, they came out of there. They said, 'Oh my God. That’s unbelievable,'" Trump said. "I had to say. We have women that are highly sophisticated here, but they used to look at Arnold as a man."

Harris has had a small lead over Trump in the national polling averages since she entered the race at the end of July and she remains ahead - as shown in the chart below with the latest figures rounded to the nearest whole number.

Harris saw a bounce in her polling numbers in the first few weeks of her campaign, building a lead of nearly four percentage points towards the end of August.

But the numbers have been relatively stable since early September, even after the only debate between the two candidates on 10 September, which was watched by nearly 70 million people.

You can see how little the race has changed nationally in the last few weeks in the poll tracker chart below, with the trend lines showing the averages and the dots showing the individual poll results for each candidate.

While these national polls are a useful guide as to how popular a candidate is across the country as a whole, they're not necessarily an accurate way to predict the result of the election. That's because there are seven swing states that are likely to decide the whole race.

Right now the polls are very tight in the seven states considered battlegrounds in this election and neither candidate has a decisive lead in any of them, according to the polling averages.

You can read more about where the polls stand here.

Caitlin Wilson
US live editor

It's a busy weekend for Republican Donald Trump and Democrat Kamala Harris.

Sunday is Harris's 60th birthday - she'll mark the occasion by appearing in an interview with famous civil rights figure Al Sharpton.

And Trump is still in Pennsylvania, hoping to convince voters there to case their ballots for him in just 16 days. He's set to rally supporters in Lancaster and expected to attend an NFL game later in the day.

Earlier this weekend, both candidates continued their swing state barnstorming. Trump was in Latrobe, Pennsylvania, where he spent several minutes talking about hometown hero and famous golfer Arnold Palmer - who the former president said was "all man", raising eyebrows on social media - and said Americans want to be "freed" from Harris.

Harris meanwhile hit up two different swing states with support from the start power of two different musicians - Lizzo joined her in Detroit, Michigan, while Usher introduced the vice-president in Atlanta, Georgia. Harris hit out at Trump for being unfit for the presidency, calling him "increasingly unstable".

We'll be bringing you all the updates from around the country today, as well as deep dives into the all-important swing states. There's a lot to come, so stick with us.