THE SNP is on course for another “remarkable electoral success” in next May’s Holyrood elections, according to Scotland’s leading political analyst.

Professor John Curtice of Strathclyde University was speaking after the party held three Glasgow City Council seats, took one from the Greens and held another on South Lanarkshire Council in a series of by-elections.

He told The National: “The 2012 local elections were, of course, not the SNP’s finest hour, so we should expect quite big swings from that baseline if the party remains as popular as it was in May or is as popular as it has been reported to be in recent polls of Holyrood voting intentions.

“But the average 17-point increase in the SNP vote is consistent with its 50 per cent vote in May and its current popularity in the polls, while the average 12-point drop in Labour support indicates that the party remains deeply unpopular.

“These local by-elections thus add weight to the message of the polls that at the moment the SNP seems well set to secure another remarkable electoral success next May.”

SNP Business Convener Derek Mackay said: “It has been an excellent performance for the SNP campaigns in Glasgow and Hamilton, with a strong swing of almost 20 per cent from Labour, which echoes the remarkable results we saw in Aberdeen last week.

“This is another strong endorsement of the work of our new SNP MPs, who are providing the real opposition to the Tories’ austerity agenda at Westminster and standing up for Scotland’s interests.”

In Glasgow, Alex Wilson, Greg Hepburn and Eva Bolander were elected in Craigton, Calton and Anderston/City respectively. In

Langside, Anna Richardson won the ward from the Greens. Across Glasgow, the SNP vote increased to 52 per cent with a 19.7 per cent swing from Labour.

In the Langside ward the first-preference voting was: SNP 2,134, Labour 932, Green 579, Conservative 379, Liberal Democrats 125, Ukip 65, TUSC 62. Here the swing from Labour to the SNP was 13 per cent. The Greens saw their share of the vote rise by 4.5 points, but it was not enough to hold the seat they had won in 2012. Turnout was 21.7 per cent.

In Calton ward, the SNP held the council seat vacated by new MP Alison Thewliss with 1,507 first-preference votes while Labour won 814, the Conservatives 129, Ukip 103, the Greens 99, Independents 47 and LibDems 18. The swing from Labour to the SNP was 25 per cent, and voter turnout was 16.1 per cent.

In the Anderston/City ward, formerly represented by new MP Martin Docherty, the SNP held the seat with 1,441 first-count votes. Other party totals were: Labour 857, Green 414, Conservative 164, LibDem 66, Ukip 43, Libertarian 12. The swing from Labour to the SNP was 20 per cent, with a 14.5 per cent turnout.

The SNP also held the Craigton ward in Glasgow with 2,674 first-preference votes. Labour won 1,643, Conservative 300, Green 136, Ukip 95 and LibDem 870. The swing from Labour to the SNP was 21.5 per cent. Turnout was 21.7 per cent.

Glasgow SNP Leader of the Opposition Susan Aitken said: “I am sure that our new SNP councillors will work hard to represent their constituents and contribute to the work of the council.

“I am delighted that so many Glaswegians are showing continuing support for the SNP and recognise that the best way to get a council which listens to citizens and delivers more of the services they want is to vote SNP.”

She added: “This result is also further evidence that voters have lost all faith in Labour and that several visits from senior party figures – including UK Deputy Leader candidates – failed to have any positive impact.”

In the Hamilton South ward on South Lanarkshire Council, the SNP held the seat vacated by Angela Crawley MP with 1,881 first-preference votes. Labour won 1,396, Conservative 349, Green 127, Christian 77, Ukip 43, LibDem 32, and Pirate 13. The swing from Labour to the SNP was 16 per cent, and turnout 26.8 per cent.

Similar swings of 20 per cent and 23 per cent from Labour to the SNP were recorded last week in two Aberdeen City Council by-elections, as well as a 25 per cent swing in a North Lanarkshire Council poll in July.

The Aberdeen polls were prompted by the resignation as councillors of Kirsty Blackman, now SNP MP for Aberdeen North, and Callum McCaig, now SNP MP for Aberdeen South.

Mackay added: “These by- elections show that people across Scotland continue to put their trust in SNP representatives to stand up for their community.

“With polls showing strong support for the SNP for next year’s Scottish Parliament elections, the SNP is in a strong position to build on our record.”

A total of 13 new SNP MPs have stepped down as councillors to focus on their Westminster roles, triggering local by-elections. Two further polls will take place next Thursday in Falkirk, where John McNall is now SNP MP, and North Lanarkshire, where Marion Fellows is the SNP MP for Motherwell and Wishaw.

The remaining by-elections will follow in August and September.