(Bloomberg) -- The arrest of the husband of Scotland’s former leader Nicola Sturgeon dealt a major blow to one of the UK’s most effective political parties, which risks unraveling just as the next general election comes into view.

Peter Murrell was questioned by detectives Wednesday in connection with a probe into the Scottish National Party’s finances. He was released without charge pending further investigation after 11 hours in custody, Police Scotland said in a statement late Wednesday.

The arrest plunges the party, which is campaigning to break up the UK with an independent Scotland, into further turmoil after Sturgeon stepped down as party leader and first minister.

The ramifications extend beyond Scotland. The SNP has dominated Scottish politics for more than a decade, most of that under Sturgeon. That’s primarily been at the expense of the UK opposition Labour Party, which then faced a far more difficult path to power in Westminster.

Scotland’s New Leader Faces Same Old Rancor Over Independence

Since her resignation, support for the SNP as well as backing for independence have dropped, potentially opening the door for Keir Starmer’s Labour to pick up seats. His party is well ahead of Prime Minister Rishi Sunak’s Conservatives in nationwide opinion polls, yet due to the UK’s political system and its district boundaries, a parliamentary majority is far from certain.

The next UK general election is due by January 2025 at the latest.

Sturgeon’s departure was always likely to undermine the SNP but subsequent events, including Murrell’s arrest, have compounded its problems. Humza Yousaf only narrowly won a leadership contest that exposed deep divisions. Despite her dominance, Sturgeon also leaves behind a patchy record on health and education, and a long-running scandal over ferry contracts.

Probe

The immediate threat, though, is the police probe. Already running for about 18 months, officers are looking at complaints that donations which were supposed to have been in a ring-fenced referendum fund, had been misappropriated.

Murrell, married to Sturgeon since 2010, had already resigned as chief executive of the SNP last month following a separate controversy over falling membership numbers. But his arrest will fuel the sense of a party in turmoil.

Police Scotland have been looking into whether £600,000 ($750,000) of donations to the SNP for independence campaigning may have been used for other purposes. Officers carried out searches at a number of addresses Wednesday as part of the probe, Police Scotland said.

The arrest — coupled with footage of police activity at the couple’s home and the SNP’s headquarters in Edinburgh — offers the most visible illustration yet of the trouble the UK’s third largest political party finds itself in. It also raises questions as to why Sturgeon stepped down when she did. 

New Leader

It’s also intensely awkward for Yousaf, whose leadership pitch as the “continuity candidate” and the perception that he was Sturgeon’s preferred choice make it trickier for the SNP to persuade voters he offers a clean break.

Scotland’s Nationalists Pick Yousaf as Leader to Unite Party

“This is a difficult day for the party,” Yousaf told broadcasters after Murrell’s arrest, adding he won’t comment on a live police investigation. The SNP also said in a statement it is conducting an internal review into its governance.

“People will have questions, there will be some concerns. Our party membership will have concerns too.” he said. “What I can commit to as party leader is that we want to be absolutely transparent.”

Yousaf’s first electoral test may come sooner than a general election. The SNP could face a special election in a key seat in Glasgow because MP Margaret Ferrier faces a 30-day suspension from the UK Parliament for breaking Covid-19 rules during the pandemic. Though that is not certain to trigger a vote, Yousaf has acknowledged retaining the seat would take “hard work.”

The outcome would be closely watched ahead of the general election. The SNP’s high point came in 2015, when it took 50% of the vote in the general election and 56 of Scotland’s 59 Westminster districts — a result that weakened Labour and paved the way for a Tory majority in the UK Parliament.

The SNP currently holds 45 seats, compared with six for the Conservatives and only one for Labour, according to the parliament website. Labour has held a double-digit lead in nationwide opinion polls for months, but is trying to overturn the Conservatives’ 66-seat working majority.

--With assistance from Emily Ashton.

(Updates with Murrell being released pending further investigation in second, changes tense in 10th paragraph)

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