Winner in 2016: Derek Mackay (SNP)

RENFREWSHIRE North and West, or at least its predecessor constituency of West Renfrewshire, is a rare example of a Holyrood seat in the western part of the central belt where the Conservatives have been competitive over the years.

Even more remarkable is that their nearest miss occurred long before Ruth Davidson got them back into the game nationally. In 2007, the Tories’ candidate was their then leader Annabel Goldie and she came within just over seven percentage points of defeating the Labour incumbent Trish Godman.

The SNP candidate, Bill Wilson, best known for challenging John Swinney’s leadership of the party a few years earlier, was pushed into third against the national trend.

However, boundary revisions and a further national SNP surge meant the Tories had missed their best chance. In 2011, new SNP candidate Derek Mackay surged to victory, with Labour not too far behind in second place and Goldie slipping to a distant third for the Tories. Due to the big nationwide swing from Labour to Tory in 2016, there was bound to be a chance that the Tories would move back into second place, and they just about did.

However, the gap between them and the SNP was a mammoth 24 percentage points, which must have been somewhat disappointing for them in a part of the world where they had almost won outright in a much less favourable year.

Part of the explanation may be that the Tories had previously benefited from a substantial personal vote for Goldie, which vanished in 2016 after she made the switch from devolved politics to the House of Lords.

Goldie is far from being the most illustrious person to have stood for election in the seat, though. In 1999, local voters also turned down the chance to be represented by the celebrated journalist and writer

Neal Ascherson, who was the standard-bearer for the LibDems, although he went on to support the Yes campaign in the independence referendum.

Since 2016, Renfrewshire North and West has been on something of a rollercoaster ride, witnessing its local MSP being appointed to one of the highest offices of the land and then being sent to the backbenches in disgrace – and indeed suspended from the SNP altogether.

Derek Mackay has seen out the last year and a bit of his time in Parliament as an independent, and the SNP will now be hoping to wipe the slate clean with their new candidate Natalie Don.

She may already have got over the toughest hurdle by winning the internal selection vote against her fellow Renfrewshire councillor Michelle Campbell, who was subsequently placed at the top of the SNP’s list in the West Scotland region.

For Don to miss out next week, the Tories would require a swing of 12% or Labour would require a swing of just over 12%. That doesn’t look realistically attainable for either party unless the swing is very localised.

In practice, the Tories may simply be hoping to emulate Goldie by reducing the gap and setting up a chance of victory in future years. Labour’s candidate is Johanna Baxter, previously best known for a somewhat over-the-top reaction to the loss of battles against Corbynites in the party’s internal structures. Her main target may be to overtake the Tories and reclaim second place.

But of course a third possibility is that nothing much will change and the 2016 result will be more or less replicated. Judging from the latest opinion polls, that may even be the most probable outcome.