Winner in 2019 of predecessor seat of Argyll and Bute: Brendan O’Hara​ (SNP)

IF there’s any constituency that perfectly illustrates the folly of the First Past The Post voting system, it’s Argyll and Bute, which is expanding this year to incorporate part of Lochaber.

There used to be a joke that the LibDems were only the fourth-most-popular party there but kept winning because other parties’ supporters felt they had no choice but to vote tactically to block each other. There was a grain of truth in that, and the SNP ended up suffering from the phenomenon more than any other party.

At one time they had been the only serious competition to the Conservatives in the old seat of Argyll. As early as 1970, well before they had substantial representation in Parliament, they finished a strong second in Argyll with 30% of the vote, almost three times higher than their national support.

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That proved enough of a springboard for Iain MacCormick, son of the legendary John MacCormick of the Scottish Covenant Association, to leapfrog the Tories in February 1974 to become SNP MP for the constituency, which he held until his party’s disastrous national result in 1979.

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So when the unpopularity of Thatcherism led the SNP to start regaining rural seats from the Tories in 1987, they should have been ideally placed to grab Argyll and Bute back. But they weren’t, and the main reason was the result in the constituency at the previous General Election four years earlier, when the Liberal/SDP Alliance, forerunners of the LibDems, had reached their UK-wide high watermark.

Ray Michie of the Alliance jumped 14 percentage points in 1983 to move into second place in Argyll and Bute, narrowly ahead of the SNP. By 1987 there was a huge push across Scotland to vote tactically for whichever party had been second to the Tories in 1983 in any given constituency. Michie was a key beneficiary, and squeezed the SNP vote heavily to gain the seat.

Her majority over the Tories was narrow, which meant that many anti-Tory voters felt they couldn’t risk voting for anyone but her in subsequent elections. Ironically she also became an attractive option for tactical votes from Tory supporters, who regarded a LibDem MP as a lesser evil than an SNP or Labour MP.

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Voters became hopelessly stuck in a trap created by an electoral system that incentivises voting negatively for the candidate best placed to beat the party you most want to lose.

What could easily have been a fleeting success for Michie in the 1980s was effectively fossilised for three decades, until the unpopularity of the David Cameron/Nick Clegg (below) coalition led tactical voters to unceremoniously abandon the LibDems in 2015 and revert to their first-choice parties.

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The result was an overwhelming triumph for Brendan O’Hara of the SNP. He has held the seat since, although he had to survive an almighty scare from the resurgent Tories in 2017.

This year, the constituency moves into uncharted territory due to national polls suggesting the SNP and Tories have both lost support at the same time. It may be that O’Hara can shore up his local support in exactly the way the LibDems used to: by arguing that a vote for anyone but himself risks a Tory win.

The Tories in turn will try to prevent their Unionist voters drifting away by pointing to their second place last time around as evidence that only they can stop the SNP. The LibDems will seek to discredit Tory hopes of victory as fantastical in current circumstances, and will suggest that their own heritage in the constituency offers a more plausible hope of a non-SNP winner.

Intriguingly, gossip from the ground suggests the LibDems are making no effort to appeal to SNP voters on an anti-Tory pitch in the way they used to, and instead are putting all their eggs in a strictly Unionist basket.

With so many tactical permutations in play, the result in Argyll, Bute and South Lochaber is unpredictable and may depart radically from national trends.

But the smart money remains on the SNP, if only due to their enviable position of starting with a decent nine-point cushion over a second-placed Conservative Party which is going backwards.