Rutherglen and Hamilton West by-election result will help set the political agenda in Scotland

Voters will have their say in Rutherglen and Hamilton West today

It has been called the most important by-election in Scotland in decades.

Today voters will have their say in Rutherglen and Hamilton West – and what they decide will have ramifications well beyond South Lanarkshire.

Political leaders from across the UK will have their eyes fixed on the constituency as the votes are counted. For the SNP, this is Humza Yousaf’s first big electoral test as First Minister. It comes amid a difficult time for his party, which has been rocked by the fallout from the police investigation into its funding and finances.

For Labour, this is a chance to demonstrate momentum ahead of next year’s general election. Victory would help show the party is back in action north of the border. Defeat would be a significant blow to its comeback narrative.

In truth, most political insiders believe a Labour victory is likely in the bag. But the party won’t want to win by the skin of its teeth. The size of the majority will be important here, too.

This moment has been a long time coming. Margaret Ferrier won the seat for the SNP in 2019 with a 5,230 majority, but was suspended by the party the following year for breaking Covid rules. She was ousted by voters in August this year following a successful recall petition – the first to be held in Scotland.

Campaigning in the seat has been going on for months. There are 14 candidates on the ballot paper – some inevitably more colourful than others – but this is a two-way fight between the SNP and Labour. The latter took it in the 2017 general election before Ms Ferrier won it back for the SNP in 2019.

Sir Keir Starmer said the by-election will be a milestone in Labour’s “hard road” back to power if the party wins. “It’s about the future of Scotland,” he told activists last week. Labour’s candidate, Michael Shanks, recently told The Scotsman that party activists had spoken to more than 30,000 people in the constituency.

Katy Loudon, the SNP’s candidate, has accused Labour of arrogance and entitlement. "They think that they have this in the bag,” she told me last month. “That does not go down very well with people, when you bring in a candidate to come round your doors and tell you that."

Both candidates cite the cost-of-living crisis as a crucial issue on the doors. The SNP has made much of apparent divisions in the Labour Party north and south of the border over issues such as the two-child benefit cap. Mr Shanks previously said he would vote to abolish the cap, but Sir Keir has said scrapping it will not be party policy going into the next general election. Mr Shanks denies there is any disagreement between the two.

“Westminster only takes notice of Scotland when the SNP wins,” Ms Loudon argued yesterday. “Vote SNP in Rutherglen and Hamilton West to let the Westminster establishment know that Scotland must not be ignored. Let’s send the Tories and Labour a message that we reject their austerity, their cruel two-child cap and rape clause, and their damaging Brexit.”

She told journalists she was feeling confident. “It’s coming from the conversations on the doorstep,” she said. “I wouldn’t be in this election if I didn’t think I was the best candidate to represent people here. What drives me is making sure that people in this area get a fair crack of the whip. That’s the message I’m taking out to people and that’s what people are looking for, and they’re responding to it well.”

Anas Sarwar, the Scottish Labour leader, pointed to the election of SNP stalwart Winnie Ewing in Hamilton in a 1967 poll, as well as the Glasgow East by-election the party won in 2008. “I believe this has the potential to be a seismic by-election and then as a launchpad as we head towards that next general election,” he said.

“We approach that with excitement, we approach that with confidence, but we do it with a hunger and desire to recognise that we have come a long way in terms of persuading people that the Scottish Labour Party is back, and we’ve still got a long way to go to earn the trust of the Scottish people, and I’m absolutely determined to do that.”

Some insiders fear the number of constituents who turn out to vote could be low. Tactical voting could also come into play, with Tory and Liberal Democrat supporters choosing to back Labour to keep the SNP out.

Scottish Tory candidate Thomas Kerr – a Glasgow councillor – said voters face “a stark choice”. He said: “By voting for me – and the Scottish Conservatives – people will ensure that they have an MP that will be fully focused on tackling their real priorities, such as the global cost-of-living crisis, reducing NHS waiting times and protecting crucial local services.”

Speaking to Scotland on Sunday at the weekend, Mr Shanks said all the candidates were “absolutely knackered”. He said: “I suspect there's a certain number of the voters who are ready for this to be over as well.”

Rutherglen and Hamilton West has been at the centre of the political spotlight over the past few months. That will soon come to an end. But the aftermath will help set the political agenda in Scotland for some time to come.