Analysis of voting in independence referendum and latest polls suggest Westminster seats at risk from ‘yes alliance’ Data: the full spreadsheet of results

Scottish Labour leaders have privately admitted they could lose a swath of key seats in Scotland after a surge in support for the Scottish National party as a Guardian analysis indicates up to 20 seats are at risk.

The analysis examines voting in the September’s independence referendum and looks at how, if there were similar voting patterns in the general election, this could affect the number of seats Labour holds in Scotland – currently 41.

Those findings are emphasised by two new polls last week that stunned Labour’s leadership north and south of the border and give the SNP record leads in a Westminster vote in the wake of its Scottish leadership crisis. One poll by Ipsos Mori gave the SNP 52% at a general election for the first time in its history.

Labour’s support slumped to its lowest level since 2007 at 23% in the Ipsos Mori poll, and down to 27% in a second by YouGov for the Times, which put the SNP at 43%, giving it a 16-point lead over Labour. Both polls took place as Labour’s Scottish leader Johann Lamont resigned after a bitter internal feud.

The polls bolster plans for a mass tactical voting campaign in May’s general election by independence activists and senior SNP figures. They want to mount vigorous campaigns to rally disgruntled Labour, Green and socialist voters in key Labour areas of Glasgow, Dundee and North Lanarkshire, which voted yes in September’s independence referendum.

A Guardian analysis has identified 20 Labour Westminster seats at risk from the so-called “yes alliance” after SNP membership more than tripled to more than 80,000 after the referendum, allowing the SNP to outgun Labour across west and central Scotland and reshaping the political landscape.

The analysis includes a Guardian map that publishes seat-by-seat data for the yes vote in each constituency, supplied where it is available by local council referendum count officers, and measures it against the majorities held by Labour in those key seats. In some seats, local council areas are identical to Westminster boundaries.

A surge of support for the SNP in the general election poses a direct threat to Miliband’s chances of winning a workable majority in May with Labour’s opinion poll lead currently too slim to guarantee an outright victory over the Conservatives.

It will also be the greatest challenge facing Scottish Labour’s new leader, widely tipped to be Jim Murphy, the party’s former shadow international development secretary at Westminster, who will be expected to resign as an MP and stand for Holyrood to become a far more credible Scottish leader.

Murphy told the Guardian the new polls posed a challenge to the party, but he insisted it would hold its current seats

“Of course it’s going to be a tough fight,” he said. “These opinion polls are a kick in the shins, but my approach is that what we have, we hold. And I am confident we will do that.”

Miliband claimed the polls showed a temporary SNP surge. “These polls are a snapshot and not a prediction,” he told STV’s Scotland Tonight on Thursday. “Let’s see where we are at the general election.”

But senior Labour leaders and strategists admit privately that a number of seats are threatened because of local pro-independence support and the post-referendum SNP surge. “I have to assume my seat is always at risk,” one sitting Labour MP told the Guardian.

A second Labour MP, Iain McKenzie in Inverclyde, who is protecting a 5,838 majority, said he had already anticipated tactical voting against him and was prepared for it

“I never look on anywhere as a safe seat,” he said. “I have always approached an election as a marginal, regardless.”

Also at risk from the SNP surge are seats that voted no but where the SNP was in second place in the 2010 general election.

Those include Edinburgh East, where a Labour MP is protecting a 9,181-vote majority over the SNP but more than 47% of voters, about 27,500 people, voted for independence – the highest yes vote in a city that was solidly no overall. There is also Falkirk, where 53.5% voted no, and in Ochil and South Perthshire, which was solidly no but sitting MP Gordon Banks is nursing a 10% majority over the SNP.

Labour’s ability to hold Falkirk has been hit hard by controversies over sitting MP Eric Joyce’s personal behaviour and the vote-fixing allegations that hit Labour’s selection process after Joyce was forced out of the party, to sit as an independent.

Robin McAlpine, director of the pro-independence thinktank Common Weal and a leading advocate of tactical voting, said a “yes alliance” could ask all pro-independence voters to back only those candidates who oppose the spending cuts being backed by Westminster’s major parties.

“Yes voters will be more motivated,” McAlpine said. “There is a fundamental hostility to Labour in former Labour heartlands and we know how dreadful Ed Miliband’s trust ratings are.”

Most Labour MPs in its heartland areas where the yes vote is strongest have substantial 30% to 40% majorities, making it far harder to predict which could be most at risk. But across those heartland areas, the SNP’s membership has soared since the referendum.

It has quadrupled to more than 9,000 in Glasgow, where yes won by 53.5% to 46.5%, and in the main towns of North Lanarkshire, where yes won by 51% to 49%, SNP membership has increased six-fold to 1,550 in Cumbernauld and by more than five times to nearly 1,000 in Coatbridge and to nearly 900 in Motherwell. In Dundee as a whole, it has quadrupled from 484 before the referendum to 2,443 now.

Prof Charlie Jeffery, the chair of politics at Edinburgh University, said the referendum campaign appeared to have disrupted conventional politics in Scotland and could lead to a dramatic change in the greater Glasgow area.

“I think we will see the SNP increase its representation at Westminster, and with that will no doubt have additional bargaining power when it comes to the detail of the new Scotland bill” offering greater tax and welfare powers to Holyrood, Jeffery said.

But the same analysis also suggests at least half of the SNP’s Westminster seats in its rural, more conservative heartlands could be at risk after every rural seat represented by the SNP in the Commons voted no on 18 September – some by a large margin. Voters in only one SNP Westminster seat – Dundee East, voted yes to independence.

A Tory source said: “These are very volatile times, and it skews the political calculus on what a marginal seat is and what it isn’t. And I think all the parties have to get to grips with that.”

The “yes alliance” proposal is being openly backed by two candidates to become SNP deputy leader, its Westminster Treasury spokesman, Stewart Hosie, and Angela Constance, a Holyrood employment minister. However, senior figures in the SNP and Yes Scotland believe the strategy could seriously backfire.

If the yes campaign turns the general election into another contest over Scotland’s constitutional future, under the stronger centre-left platform favoured by incoming SNP leader Nicola Sturgeon, pro-union voters would themselves vote tactically to block a nationalist campaign and support the strongest pro-UK candidate.

Some SNP officials fear that the estimated 180,000 SNP voters who voted against independence in the referendum, but would back the party on day-to-day issues as Scotland’s champion in the UK, would support other parties if independence was back on the election agenda.

The SNP rural seats then at risk include Perth and North Perthshire, which was confirmed by David Cameron earlier this month as one of the Tories’ top targets in Scotland; the neighbouring seat of Angus, another Tory target, which voted against independence by 56.3% against 43.7%; and the SNP-Labour marginal of Western Isles, where voters surprised the SNP by rejecting independence by 53.4% to 46.6%.

Perth and North Perthshire is held by the SNP’s culture spokesman, Pete Wishart, who said a mass tactical voting campaign, which has been endorsed by several SNP MSPs at Holyrood, including Alex Salmond’s adviser, Joan McAlpine, was “something worth testing”.

The equivalent council area of Perth and Kinross voted no by 60.2% to 39.8%. Wishart denied that would backfire on the SNP in rural areas because it would put Labour in the untenable position of asking its voters to back the Tories.

He said the yes vote in his constituency area was higher at 43%; SNP membership has now jumped there from 409 before the referendum to 2,518. “The last time I was given the honour of being their number one target seat, I trebled my majority over them,” he said.

But the risk of a backlash against sitting SNP MPs from anti-independence voters has led the SNP’s senior strategists to play down the prospects of a formal yes alliance coalition, even though they believe the party is now far stronger after the referendum.

They say Labour is likely to hold most of its seats in Glasgow, and their Lanarkshire and Ayrshire seats, because they hold substantial majorities based on high turnouts of 60% and above. “The SNP has never in its history won a Glasgow seat in a UK general election,” said one senior figure. “They’re not necessarily out of our reach, but would be a heck of a challenge to pull off.”

That source added that independence was not on the agenda at the general election and voters knew the SNP had no chance of forming a UK government or winning cabinet places, making it harder to appeal to yes voters who supported other parties.

The Scottish Green party, which will come under the greatest pressure to back a yes alliance, is also unlikely to endorse a formal tactical voting campaign because it wants to preserve its political identity.

But Labour sources admit they believe the party faces a far tougher battle defending their majorities in central Scotland, in large part because Gordon Brown is no longer party leader, and Ed Miliband has failed to win the same respect or loyalty among Scottish voters.

Ipsos Mori put Miliband’s popularity rating at 18%, lower than Labour’s support. The Times YouGov poll said only 15% of Scotland’s voters like him, barely half of Labour’s vote.

A source said Scotland’s higher Labour vote in 2010 was based on a “Brown bounce” - a combination of historical loyalties to Brown and a reflex response to the backlash against him in England. “We will be starting on the basis that there’s now no such thing as a ‘typical Labour voter’ any more,” he said.

A key factor in many local contests will be the strength of the Lib Dem vote after the collapse in support under UK leader Nick Clegg.

While all 11 Lib Dem MPs have seats in areas that voted no in the referendum, the party came second in several key Labour seats, including the most marginal seat in Scotland, Edinburgh South. Labour will be heavily targeting Lib Dem voters to stop them switching to the SNP.



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