If you take a look at the Rutherglen and Hamilton West by-election results, you'll see they played out like this:
GLORIA ADEBO Scottish Liberal Democrats 895
BILL BONNAR Scottish Socialist Party - Free Public Transport 271
GARRY PATRICK COOKE 6
ANDREW VINCENT DALY Independent 81
CAMERON EADIE Scottish Green Party 601
PRINCE ANKIT LOVE EMPEROR OF INDIA 34
NIALL FRASER Scottish Family Party - Fearlessly Speaking Truth 319
EWAN HOYLE Volt UK - The UK in Europe 46
THOMAS JORDAN KERR Scottish Conservative and Unionist Party 1,192
KATY LOUDON Scottish National Party (SNP) 8,399
CHRISTOPHER ANTHONY SERMANNI Scottish Trade Unionist and Socialist Coalition 178
MICHAEL SHANKS Scottish Labour Party 17,845
DAVID STARK Reform UK - Changing Politics for Good 403
COLETTE WALKER Independence for Scotland Party 207
https://www.southlanarkshire.gov.uk/info/200237/elections/2183/rutherglen_and_hamilton_west_by-election_results, Margaret Ferrier won the seat from Labour with 23,775 votes. Labour's Ged Killen got 18,545 votes. The Tories' Lynne Nailon got 8,054 votes.
In the by-election, the Tory vote collapsed, to the extent that their candidate lost his deposit. Allowing for a reduced turnout, it's not a stretch to see the result reflecting tactical anti-SNP voting, implying that Tory voters held their noses and voted for Michael Shanks. It looks like SNP voters stayed at home - maybe not surprising given the extended period between Margaret Ferrier being convicted for her breach of COVID rules and finally being suspended from parliament and the recall petition that triggered the by-election. (As an aside, her conduct was inexcusable, but she paid a very heavy price compared to various Tory politicians who are still being held to account for their own transgressions.)
The constituency had never been a safe SNP seat anyway, having see-sawed between Labour and the SNP in recent alternate elections.
South Larkshire Council, which includes the constituency, has a party breakdown that looks like this:
Although the SNP is the largest party,
the council is run by a Labour-Tory-Lib Dem "partnership" (Labour shy away from calling it a coalition). That's democracy for you.
Elsewhere, Ian Murray, Labour's only Scottish MP until the by-election, has famously repeatedly held his seat in a well-to-do part of Edinburgh South with the help of Tory tactical voters.
With even the current mere sniff of the possibility of taking power, rifts have emerged between Murray, who assumes he will take over from the abominable nob Tory Alister Jack as Secretary of State for Scotland, and Scottish Labour Leader Anas Sarwar. Murray's intention to continue Jack's interpretation of the role as a viceroyship is indicated by his current disagreement with Sarwar over the role and extent of devolution, awkwardly straddling the line between what policies Starmer wants for the UK and what Sarwar, supposedly in lockstep with Starmer, according to Starmer at least, proclaims as Scottish Labour policy:
Both Starmer and Sarwar right over two-child benefit cap, says Murray
...
Sir Keir Starmer would not pledge to drop the controversial measure – which has been criticised by opposition politicians, including those from his own party, and leading poverty charities – last week.
Within 24 hours, however, Scottish Labour leader Anas Sarwar said he and his MSPs would “press” the UK leader to commit to scrapping the cap if he wins the next general election.
https://www.independent.co.uk/news/uk/ian-murray-labour-scottish-scottish-labour-msps-b2379515.html
Labour Shadow Scottish Secretary rejects case for more powers for Holyrood
...
Ian Murray said the focus should be on the Scottish Government using their existing powers better.
He also rejected claims MSPs should have the legal right to set a higher minimum wage.
...
Party insiders have told the Record there are tensions between UK and Scottish Labour on transferring new powers to Holyrood.
The Scottish party backs the devolution of employment law, with leader Anas Sarwar saying it could be ‘phase 2’ of a Keir Starmer Government.
https://www.dailyrecord.co.uk/news/politics/labour-shadow-scottish-secretary-rejects-31175267
Murray and Sarwar also appear to differ on issues like the Gender Recognition Reform at Holyrood, which had cross-party support until the Tories, and seemingly latterly Labour, chose to use it as a wedge issue.
We've yet to see which version of Michael Shanks MP the electorate have got for their votes, but before coming an MP, he showed signs of being something of a wild card and loose cannon on various issues where Starmer's taken a hard line.
These sorts of tensions will only multiply if Labour do manage to win more Scottish Westminster seats, so they should be careful what they wish for.
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