New Labour MP Keir Mather and party leader Sir Keir Starmer are about to address supporters in Selby, following their by-election win there.

We'll let you know here what they have to say. You can also watch them live by pressing the Play button on the streaming link at the top of this page.

Image source, PA Media

While we await some comments from Labour in Selby and Ainsty - a seat won by the party overnight - let's quickly answer a question that many of you have been searching this morning.

We expect the general election to take place next year - although an exact date is yet to be set.

Here’s a quick guide to the rules around how and when it could happen:

• General elections - in which all 650 MPs are elected to the Commons - are held no more than five years and one month apart
• The current parliament first met on 17 December 2019. The next election is therefore due to happen no later than 28 January 2025 (taking into account the time required to run an election campaign)
• Parliament will be dissolved on Tuesday 17 December 2024 as a default - though early elections can be called, which require the prime minister to make a request to the King
• An early general election could also be forced if the incumbent PM loses a no confidence vote

Peter Barnes
BBC political analyst

One interesting feature of the results of the three by-elections was that there was evidence of tactical voting between Labour and Lib Dem supporters.

In Uxbridge and South Ruislip, and Selby and Ainsty - where Labour were the main challengers to the Conservatives in both seats - the Lib Dem vote was down five percentage points.

But in Somerton and Frome, where the Lib Dems were in contention, Labour's vote was down 10 points.

If that trend was repeated at a general election it could have a significant impact on the overall result. The effect would be to magnify Labour and Lib Dem gains, and Conservative losses.

Professor Rob Ford from Manchester University has calculated , externalthat if there was a uniform national swing of 10% from Conservatives to Labour at the next election, with other parties staying at 2019 levels, the two parties between them would win just over half the seats.

But if tactical voting is added to the equation, even at relatively modest levels, both parties would pick up extra seats.

And if half of Labour and Lib Dem supporters voted tactically in constituencies where their favoured party is in third place, the effect would be greater: the two parties between them would have a comfortable majority in the House of Commons.

This analysis doesn't take into account boundary changes which are scheduled to come into force in the next few months but the overall picture will still be the same.

Labour/Lib Dem tactical voting will be bad for the Conservatives' chances.

In a short time, we expect to hear from Keir Mather, the winning Labour candidate in Selby and Ainsty.

Earlier, Mather's mum said "never say never" about him becoming prime minister.

Jill Tambaros says Mather was named after Keir Hardie, who founded the Labour Party (after whom the current party leader Sir Keir Starmer is also named).

Her son has become the youngest MP in the House of Commons after winning the North Yorkshire seat.

She adds that Mather has always loved politics and enjoyed watched BBC news as a young child to keep up with current affairs.

• Read our profile on Keir Mather here

Earlier, we reported in a push notification and elsewhere that Labour’s win in Selby and Ainsty represented the biggest ever by-election swing to the party, but that wasn’t quite right.

It was the biggest Tory majority overturned by Labour at a by-election since 1945.

It was also the second-biggest swing to Labour at a by-election since 1945. And its biggest swing at a by-election since 1994.

Earlier this morning, the Newscast team recorded a live episode all about the overnight by-election results.

Host Adam Fleming spoke to a host of BBC journalists, including political editor Chris Mason, political correspondent Alex Forsyth and Radio 2 presenter Jeremy Vine.

• Catch up on BBC Sounds

Image source, PA Media

We've been bringing you some comments from the Lib Dem side - and here's a bit more about Sarah Dyke, who's been elected as the new MP for Somerton and Frome.

According to her website, Dyke comes from a farming family who have lived in the area for over 250 years.

She has worked in the agricultural industry and made the difficulties faces by local farmers a central issue in her campaign.

She was previously a councillor on South Somerset District Council, where she held a portfolio focused on the environment and the council's zero-carbon targets.

Chris Mason
Political editor

A former cabinet minister on the right of the Conservative Party tells me:

"The eye-watering swings against us in Selby and Somerton show there needs to be a complete change of direction. We should be cutting taxes, reducing the size of government, reining in Whitehall and delaying (the transition to) net zero (emissions).

"Uxbridge provides no get-out-of-jail-free card for Rishi. The result there shows that when we are Conservative - cutting taxes and opposing new regulations like Ulez - we are popular.

"Tired ministers responsible for the Government’s failing social democratic policy agenda like (Michael) Gove and (Jeremy) Hunt need to be replaced by Conservatives like Priti Patel and Jacob Rees-Mogg.

"It is becoming increasingly clear that a failure by the party leadership to act now and change course risks electoral armageddon for the party at the next election."

Watch the moment the Liberal Democrat leader Ed Davey staged a stunt with a "cannon" to celebrate his party winning the Somerton and Frome by-election.

Alongside winning candidate Sarah Dyke, he celebrated the party's gain by labelling the government a circus - and calling for a general election.

Davey continues by saying the key policy focuses for the Liberal Democrats are the NHS, economy and the environment.

He says he is on the side of the voters, and wants to stand up for things that matter to them.

“We stand for a fair deal for people, we’re fighting for them. They’re not getting a fair hearing from the Conservatives.”

He adds: "I think that national message is cutting through".

Speaking to the BBC's Jonathan Blake after his celebration "cannon" stunt, Ed Davey says the Lib Dems are grateful for Labour and Green voters who "lent us their support" and voted tactically for his party.

He says the Lib Dems won't be complacent or take voters for granted, but he accuses the government of doing so.

Davey adds there are 15 seats in the West Country with smaller Tory majorities than the one they've just overturned in Somerton and Frome.

Image source, PA Media

Ed Davey has just held one of his characteristic post-election victory stunts; this time showcasing a blue "cannon" (made of cardboard or similar) emblazoned with text which reads: "Get these clowns out of number 10".

After lighting a fuse on the "cannon", he holds a loud countdown from before confetti is fired into the air.

How well it compares to Davey's past use of tractors, blue walls and other props - we'll have to leave to you, the audience, to judge.

Speaking in front of a crowd of cheering supporters, Davey says people are angry with the current situation in the UK.

He says people are "working hard to make ends meet", and struggling with basic necessities, such as seeing a GP or getting a dentist appointment.

Meanwhile, he says people see that the Liberal Democrats are "listening to them". The public sent a "powerful" message to the Conservative Party by not voting for them in yesterday's by-elections, he adds.

"They’re fed up of these Conservative clowns, and their political circus is not helping people", he says.

Davey tell supporters that he is "really starting to like by-elections."

Standing alongside newly elected MP Sarah Dyke he says: "What we've achieved here is nothing short of spectacular in our liberal heartland of the south-west."

Image source, PA Media

Leader of the Liberal Democrats Ed Davey is just sharing his thoughts on the party's victory in Somerton and Frome in Somerset now.

We'll bring you his comments here, so stick with us.

Nick Eardley
Chief political correspondent

London's Ultra Low Emissions Zone (Ulez) has been blamed for Labour failing to win Uxbridge.

Both Labour and the new Conservative MP say it was the deciding factor.

Chatting to people close to Sadiq Khan, there is no sense of a change of position. They say the expansion was a hard decision but is ultimately the right one.

What’s striking though is that the Labour leadership seem to be distancing themselves from the policy. Clearly there is unease at the impact it has had and senior figures want to “reflect”.

Nick Eardley
Chief political correspondent

A source close to Mayor of London Sadiq Khan has defended the Ulez scheme as a "difficult decision" needed to "save the lives of young and vulnerable Londoners".

A source close to Sadiq Khan tells me: “Winning Uxbridge and South Ruislip was always going to be a struggle for Labour. Labour hasn’t won this seat for five decades and Tony Blair didn’t even win it during the 1997 landslide."

“Sadiq has always been clear that expanding the Ulez was a really difficult decision, but necessary to save the lives of young and vulnerable Londoners.”

Image source, .

There's been one key thing on the minds of BBC Radio 5 Live listeners this morning: London's Ultra Low Emissions Zone (Ulez).

Some calling in to Nicky Campbell's programme say the government needs to provide financial support so people can afford cars that can comply with the low-emissions legislation. (It's due to be extended to Uxbridge - something the winning Conservative candidate in the seat opposed.)

Paul from Doncaster says: “We all accept climate change. We all know we need to do something about it. But we need help. We need help to do it."

Tony in Ruislip says he feels there's been a communication breakdown in explaining which cars are - and are not - Ulez-compliant. He says he feels like Ulez is a "fundraising exercise".

The Mayor of London has created a £110 million scrappage scheme, external to help Londoners scrap high-polluting vehicles which comes into place from August.

Eligible participants can receive up to £2,000 for scrapping a car.

Yasmin Rufo
Reporting from Uxbridge

People may have thought that Boris Johnson resigning from his seat in May would have made him no longer relevant to the residents of Uxbridge - but instead he’s still front and centre in many minds here.

Paul Burn, 37, tells me he wants Boris back. He said the former prime minister “really cared about the people”.

He is now worried that the new MP, as a backbencher, will have very little influence to make a change in the area.

“Uxbridge will probably be forgotten about," he says. "No one will care about us now."

Yasmin Rufo
Reporting from Uxbridge

Many people in Uxbridge this morning are still processing the results from last night.

One man tells me he’s shocked that Labour didn’t win the election and thought it was a given that “residents wanted a real change".

Others, who voted Conservative, are delighted that Steve Tuckwell won the election.

They say they voted for him as they “hope he will be the man to stand up to Sadiq Khan’s Ulez expansion".

• Read more from Yasmin here