If you are just getting up and joining our live by-election analysis, here are the main headlines:

• Labour has defeated the SNP to win the Rutherglen and Hamilton West by-election
• The party's candidate, Michael Shanks, took the Westminster seat with 17,845 votes
• That was more than double the number polled by the SNP's Katy Loudon
• The result was a swing of 20.4% from the SNP to Labour
• Shanks said: "It's truly the honour of my life to be elected to serve to people of Rutherglen and Hamilton West."

• Scottish Labour leader Anas Sarwar said it was a "seismic" night and his boss Sir Keir Starmer echoed this by saying it was "time for change"
• First Minister Humza Yousaf accepted his party had a disappointing night
• The Scottish Conservative candidate Thomas Kerr lost his deposit
• Scotland's first recall by-election was triggered after constituents voted to oust former SNP MP Margaret Ferrier, who breached Covid rules

The conundrum of tactical votingpublished at 05:44 British Summer Time 6 October 2023

05:44 BST 6 October 2023

Philip Sim
BBC Scotland political correspondent

The way this ended as a two-horse race will raise questions about whether tactical voting was a factor.

It certainly has been in Scotland of late - in the 2019 election, almost every seat became a two-party contest between the SNP and whoever was most likely to challenge them locally.

Labour have probably benefited here, but would the same happen in a general election? The worry for the Conservatives in particular is that it might continue in a lopsided fashion.

After years of campaigning as opposition to the SNP, Tory voters might back Labour in seats where they are best placed to challenge them.

But will Labour and Lib Dem supporters be willing to vote Tory in the not-insubstantial list of SNP-Conservative marginal contests, when their whole general election campaign will be about kicking Rishi Sunak out of office?

It’s not just the SNP who have some tough questions to ponder following this result.

The Rutherglen and Hamilton West constituency has changed hands between the SNP and Labour at each of the past three general elections.

The seat in South Lanarkshire was created for the 2005 general election.

Before then the constituency, which had slightly different boundaries, was known as Glasgow Rutherglen.

Image source, .

Anas Sarwar described Labour's by-election victory as seismic - and here is a major reason why.

While the ballot papers were still being counted, the Scottish Labour leader suggested the vote could swing by about 14% in his party's favour.

In the end, his bold prediction was actually short of the mark - with a swing of more than 20% to Labour from the SNP recorded.

Image source, EPA

We've mentioned several times how this by-election result is set to influence strategies for the next UK general election.

A total of 650 seats will be up for grabs as the old guard of MPs and the Westminster rookies look to secure their place in the House of Commons.

So, when will that vote be?

Well, general elections have to be held no more than five years apart.

Therefore the next one will have to be held before January 2025.

This will be five years from when the current Parliament first met back in December 2019, plus the time required to run an election campaign.

However, a prime minister can call an early election if they want to.

Philip Sim
BBC Scotland political correspondent

The coming general election has been characterised in Scotland as a struggle between the SNP and Labour.

This is fair in that there are no direct Labour-Conservative contests north of the border, with the SNP in first or second place in every seat.

But there are also not a huge number of compelling SNP-Labour clashes in prospect either.

There are 22 seats in Scotland which could be considered marginal – where a single-digit majority of under 10% is being defended.

Of those, there are actually only four which are a straight fight between the SNP and Labour.

Rutherglen and Hamilton West remains one of them.

Kirkcaldy and Cowdenbeath is also in there at a 2.6% majority, East Lothian is at 6.6%, and Glasgow North East is at 7.5%.

It goes up to five if you include Airdrie and Shotts, where the SNP’s lead was cut to 8% in a by-election in 2021.

But if Labour is to make significant gains in Scotland, it is going to need a bigger swing consistently around the country if it is to start picking up other seats.

SNP deputy leader Keith Brown is in no doubt that Labour has benefitted from tactical voting by Tory voters in this by-election.

He says: “As the Tories face the prospect of losing all their seats in Scotland, with a devastating result that saw them lose their deposit, it's Sir Keir Starmer’s pro-Brexit Labour party that benefitted from support from Tory voters."

Mr Brown says the SNP would work hard to re-earn the trust of voters who had switched to Labour.

Party leaders to face conferences after by-electionpublished at 03:42 British Summer Time 6 October 2023

03:42 BST 6 October 2023

Philip Sim
BBC Scotland political correspondent

This by-election falls right in the middle of party conference season, with the gatherings of the two key players still to come.

The Labour conference is this weekend, with Sir Keir Starmer heading to Liverpool on a high – presumably via a quick trip to visit his newest MP in Scotland.

This will perhaps be a fitting set up for an event where he is expected to establish exactly what he wants a Labour government to stand for – having promised to set out a hopeful vision after months of refusing to commit to any expensive new projects.

The SNP, meanwhile, will meet in Aberdeen next weekend - and have rather more questions to answer after this defeat.

Humza Yousaf was hoping to swing delegates behind his vision of an independence strategy, a job which may be made all the harder if winning lots of seats at the next election looks a more challenging prospect.

Image source, PA Media

Labour leader Sir Keir Starmer using the same winning slogan as the party's Scottish boss Anas Sarwar as he says: "This is a seismic result.

"People in Rutherglen and Hamilton West have sent a clear message - it is time for change."

Sir Keir adds: "I have always said that winning back the trust of people in Scotland is essential.

"Tonight's victory is the culmination of three-and-a-half years of hard work and humility on that journey."

What does this defeat mean for Humza Yousaf?published at 02:45 British Summer Time 6 October 2023

02:45 BST 6 October 2023

Philip Sim
BBC Scotland political correspondent

This result is clearly not what the new leader would have wanted, especially given the SNP’s run of electoral dominance under his predecessor Nicola Sturgeon.

Indeed, Sturgeon may have set the bar impossibly high in that regard, having seen her party through a run of elections where the Conservatives were dominant UK-wide, and where Brexit and constitutional clashes provided key fodder for anti-establishment campaigns.

Yousaf, meanwhile, has come in the door at the moment where it’s Labour who are able to pitch themselves as the force of insurgent change at Westminster – at the same time as his SNP are finding it increasingly hard not to be seen as the long-standing establishment at Holyrood.

The SNP will always have independence to fall back on, and argue that is the “real change” that only they can offer.

But if the electorate buys 2024 as a contest about who forms the next UK government, it could leave them in an awkward position.

This result may not have been entirely unexpected, given the general drift of the polls, but it will put pressure on Yousaf to cement a strategy which can deliver better results at the national election.

Image source, PA

SNP leader, and Scotland's first minister, Humza Yousaf accepts, external it was a disappointing night for his party.

He says: "Circumstances of this by-election were always very difficult for us.

"Collapse in the Tory vote, which went straight to Labour, [was] also a significant factor."

The first minister adds: "We lost this seat in 2017, and like 2019 we can win this seat back."

Yousaf says his party will now "reflect on what we have to do to regain the trust of the people of Rutherglen and Hamilton West".

Angus Cochrane
BBC Scotland News

Scottish Tory candidate Thomas Kerr says he is disappointed after his party lost its deposit, winning just 1,192 votes.

He says tactical voting “squeezed” Conservative support, with voters keen to “send a message” to the SNP.

He predicts voters will return to the Tories in future elections.

Angus Cochrane
BBC Scotland News

Image source, Getty Images

Anas Sarwar was exuberant as candidates, party officials and journalists gathered to hear the result.

There were big smiles, jokes and bear hugs. The Scottish Labour leader suggested the vote could swing by about 14%.

His optimism was well founded and even exceeded, with a swing of more than 20% recorded.

Jackie Baillie, Scottish Labour's deputy leader, tells BBC Scotland News that voters want change.

She says the Rutherglen and Hamilton West seat has gone back and forward three times in recent elections, and so it was always going to be a challenging seat.

But, she says, voters responded to Labour's "positive agenda" and "stood on the basis of hope".

"The people... said very clearly that they want Labour and they want change."

Keith Brown accepts "this is a very good victory for the Labour party".

However, the SNP's deputy leader points out: "This moves Labour from one seat to two seats in Scotland.

"The SNP has over 40 seats."

The result does highlight a challenge for the SNP, says Brown, who accepts his party "has work to do".