The National:

Winner in 2016: Roseanna Cunningham (SNP)

ASSUMING John Swinney is re-elected, he will eventually overtake Roseanna Cunningham as the longest-serving incumbent SNP parliamentarian. Cunningham, the Environment Secretary, is standing down as the MSP for the neighbouring constituency of Perthshire South and Kinross-shire after a combined total of 26 in the UK and Scottish Parliaments.

She first arrived at Westminster a couple of years ahead of Swinney, simply due to the chance factor of the old Perth & Kinross constituency – where she had unexpectedly come up short in 1992 – falling vacant after the death of veteran Tory MP Sir Nicholas Fairbairn in 1995.

The transition from Fairbairn to Cunningham was something of a culture shock, given that the former was a maverick right-winger who dressed like an aristocratic refugee from the 19th century, and the latter is a feminist republican left-winger. In complete contrast to the relatively easy ride Swinney has had, the Tory tradition in Perthshire has proved a major problem for Cunningham in maintaining her tenure over the years.

READ MORE: Yes election 2021 #3: Smart money on Swinney to see off Fraser in Perthshire North

Since switching to Holyrood, her only truly comfortable re-election was when the SNP won an overall majority in 2011 – on that occasion her margin of victory over the Conservatives was a thumping 23%.

In the other four elections she’s led something of a charmed life, with the margin ranging from just 2% to 7%.

Perhaps surprisingly, the closest result didn’t come in the Ruth Davidson surge year of 2016, but way back in 2003 when the Tories were still in the doldrums nationally, although admittedly in those days the constituency had different boundaries.

The concern must be that the loss of any personal vote Cunningham has built up could be enough to push the Tories slightly ahead. But the counter-argument is that the new SNP candidate, Jim Fairlie, is actually a much more natural fit for the constituency. As a local sheep farmer, he may be more reassuring to rural voters and to small “c” conservatives. Unless Tory support takes a nosedive in the polls over the coming weeks, though, it seems inevitable that this will be yet another close-run thing. As long-term incumbents, the SNP are probably entitled to be considered marginal favourites, but it could go either way.