DENYING the SNP an overall majority was a “collective effort” by Unionists, according to John Curtice.

The polling expert was writing in The Scotsman after the SNP and Scottish Greens won a total of 72 seats in Holyrood on a record turnout for the Scottish Parliament elections of 63% – 10% higher than the previous average.

Curtice said the SNP’s lack of an outright majority was because Unionist voters voted for a party in each constituency that had the potential to beat the SNP.

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He said: “Denying the SNP an overall majority was, indeed, a collective effort – at least on the part of Unionist voters, who on the constituency ballot demonstrated a remarkable willingness to back whichever pro-union party appeared to be best placed locally to defeat the SNP.”

Curtice said in constituencies where the Tories started off in second place to the SNP, the party’s vote increased on average by three points, while Labour’s support fell by two points. But where Labour were the main challenger, the SNP increased by a point, while the Conservatives fell back a point.

“These movements, however, were too small to deny the SNP any of the seats that they were defending, most of which were safe anyway,” he went on.

The SNP achieved a record fourth term in government with 64 seats, 48% of the constituency vote and 40% of the list vote.

But Curtice said anti-SNP tactical voting was successful in SNP target seats like Eastwood where former Tory leader Jackson Carlaw was re-elected in Eastwood after Labour’s vote slumped by a massive 15% from 2016. Carlaw received 17,911 votes beating the SNP’s Colm Merrick who netted 15,695. Labour got just 6759, taking third place.

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In the SNP target seats of Edinburgh Western and Edinburgh Southern unionist supporting voters also swung behind what they regarded as the strongest pro-UK party in the area.

Tactical voting saw support for LibDem Alex Cole-Hamilton rise to 25,578 votes – a 13% rise on his 2016 result.

The SNP’s Sarah Masson received 15,693 votes while Labour netted just 2515 and the Tories 2798 – with falls of 4% and 8% respectively. Turnout was a massive 71.5%.

In Edinburgh Southern – another key target seat for the SNP – Labour’s Daniel Johnson was returned to Holyrood.

Johnson was elected with 20,760, a 10% increase on his 2016 result.

The SNP’s Catriona MacDonald took 16,738 votes, increasing the party’s vote share by 4%.

However, the Tory candidate Miles Briggs saw his vote share tumble by 14.5% while the LibDems also fell by a percentage.

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The results also suggest significant tactical voting in North East Fife. LibDem leader Willie Rennie took 22,163 with 55% of the vote – up 11% on 2016.

Rhuaraidh Fleming for the SNP came second on 14,715 – up 3% on the last election, while the Labour and the Tories saw falls of 3% and 10%.

“These patterns had a decisive impact on the outcome,” Curtice went on. “They helped the Conservatives to defend successfully both Aberdeenshire West and Eastwood, while Labour were able to hold Dumbarton and Edinburgh Southern.

“Because the SNP did not win any list seats in the regions in which these four seats are located, an SNP gain in any one of them would have taken the SNP past the 65 mark. In short, anti-SNP tactical voting by Unionist voters denied the SNP an overall majority.”

But Curtice said Labour’s lack of a position on Scottish independence was a “precarious strategy”.

He said: “In truth, Labour’s attempt to attract voters by asking them to leave to one side the issue that most of them seem to have regarded as the most important in the election was always at risk of being a precarious strategy.

"It thus looks as though Labour may well have lost ground on the list vote because some of the party’s potential voters were attracted by the more strident opposition to the SNP being articulated by the Conservatives and thus heeded the Conservatives’ call to vote for them on the list.”