But now Ms Sturgeon, who became SNP leader and Scotland’s first minister in 2014, is stepping down as the contest to replace her has split the party, leading to her husband’s abrupt resignation.
Mr Murrell, 58, who has been party leader since 1999, was the man responsible for the day-to-day running of the SNP, which was once the UK’s second largest party.
This job meant that Mr Murrell was one of the most influential people in Scotland policydespite never having been an elected politician or a figure in front of the cameras.
READ MORE: Peter Murrell to step down as SNP chief executive with immediate effect
However, he announced yesterday that he was stepping down with immediate effect amid a row over party membership and transparency.
It is almost a quarter of a century since he succeeded Michael Russell, the current SNP president, as the party’s chief executive, who is now taking over his job on a voluntary basis until a permanent successor is recruited.
Before that, Mr Murrell worked in the constituency of former SNP leader and First Minister Alex Salmond.
In 2010, Mr Murrell married Ms Sturgeon, then SNP deputy leader and deputy first minister, with Mr Salmond, then first minister, among the guests.
Mr Murrell is seen by many as a key player in turning around the party’s fortunes, helping to modernize the SNP’s operations.
Although membership has fallen from a peak of around 125,000 in 2018 to a recently revealed total of 72,186, the party remains the largest and most dominant political force in Scotland.
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And with Mr Murrell and Ms Sturgeon at the helm, the SNP has cemented its electoral dominance, having been in power at Holyrood since 2007 and winning every election north of the border since then.
However, critics of the SNP under Ms Sturgeon, both inside and outside the party, have long questioned whether it is appropriate for the key roles of leader and chief executive to be held by the same couple.
Hearings at Holyrood in late 2020 and early 2021 into allegations of harassment brought against Mr Salmond led to further scrutiny of Mr Murrell’s role.
He was once accused of giving contradictory evidence to a committee investigating the Scottish Government’s mishandling of harassment allegations against Mr Salmond.
Nicola Sturgeon and her then fiance Peter Murrell at their home in 2010. Photo by Nick Ponty/The Herald.
The investigation was launched after Mr Salmond won a judicial review against the Scottish Government over its handling of two sexual harassment complaints. The court Sessions ruled that the investigation was unfair and tainted by obvious bias. He awarded him £512,250 in legal costs. Mr Salmond was later acquitted of separate criminal charges following a trial at the High Court in Edinburgh.
During his evidence to the committee, Mr Salmond claimed there was a conspiracy against him which included Mr Murrell, the SNP’s chief operating officer Susan Ruddick, the SNP’s compliance officer Iain McCann and Ms Sturgeon’s chief of staff Liz Lloyd.
He cited text messages sent by Mr Murrell which were later received by Kenny MacAskill, the former SNP justice secretary who is now Mr Salmond’s Alba MP.
One message from Mr Murrell, dated 25 January 2020, said it was a “good time to put pressure” on the police as they were “twiddling their fingers” during an apparent lull in the investigation.
READ MORE: The SNP is calling for the race to continue in a “positive spirit” as Russell steps in
Another said: “The more fronts [Salmond] we have to fight for the better for all the complainants. Thus [Crown Prosecution Service] action would be good.’
Mr Salmond claimed they were motivated by the judicial review, which they saw as disastrous for Ms Sturgeon, and claimed they went fishing for police complaints to give impetus to the criminal investigation which began in late 2018.
He said the aim was for the police investigation to “overtake” the judicial review, allowing the Scottish Government to suspend it, or “insist” or obscure the loss of the judicial review by its own court.
Mr Murrell rejected Salmond’s claims that the texts proved a conspiracy, but admitted in evidence that the language was inappropriate and “indecent”. He said: “To me it shows how upset I was at the time.” During her testimony to the committee, Ms Sturgeon said the plot was “strange”.
In their final report, the MSP rejected Mr Salmond’s allegations of interference with a police investigation and conspiracy.
Separately, questions have been raised about the whereabouts of £600,000 donated to the SNP’s independence campaign, with Police Scotland confirming they were investigating last year.
Meanwhile, Mr Murrell lent the party £107,620 in June 2021 to help with cash flows after the last Scottish election, and reports last year showed around half of that money had been repaid by October 2021.