The possibility of Nicola Sturgeon’s party failing to become the kingmaker after the general election has been raised by a poll-of-polls compiled by Professor John Curtice, one of the UK’s leading election experts.
Curtice’s analysis of opinion polls carried out in the past week puts Labour in line to win 302 seats and suggests the Lib Dems are heading for 20.
Such an outcome would put the two parties within a hair’s breadth of achieving the 323 seats required for a majority in the House of Commons.
A Labour/Lib Dem package would attract the support of three SDLP MPs in Northern Ireland and would also be backed by left-leaning Lady Hermon, the former Ulster Unionist who is now an independent and is defending her seat in North Down.
An alliance of that nature would also ensure a Labour-led administration should Sinn Fein lose Fermanagh and the number of MPs required for a majority goes up to 324.
“If either Labour or Tories can get to the 300 mark, the Nats’ acquiescence is no longer required. The crucial question is can either of them get to the 300 mark?
“This poll-of-polls suggests Labour can,” said Curtice, professor of politics at Strathclyde University.
Last night the analysis was welcomed by the Lib Dems, even though a return of 20 MPs would still represent a dramatic reduction from the 57 seats Nick Clegg’s party won at the 2010 election.
The Scottish Lib Dem leader Willie Rennie claimed Curtice’s analysis suggested the SNP would be frozen out when it came to forming a government after next month’s election.
Rennie said: “The national polling falls short of our expectations but even John Curtice’s analysis that the Lib Dems could hold the balance in a hung parliament shows what is possible.
“Even on the pessimistic outlook the Liberal Democrats would be critical to the success of such a government, the SNP would be irrelevant.
“The national polling is not reflecting the local variations with Lib Dem concentrations of support. There is a route to victory for every one of our candidates in every single Lib Dem held seat in Scotland. It’s a straight choice between the Lib Dems and the SNP.
“With Professor Curtice’s analysis the real question for voters in those eleven Lib Dem seats is this: if they want a stable coalition that delivers more powers for Scotland, balances the books and invests in the NHS they need to back the Liberal Democrats as they won’t get that with the SNP.”
The SNP has based its election campaign on the idea that a large number of Nationalist MPs at Westminster will be able to prop up a Labour government and deny David Cameron a chance to get back to Downing Street.
The SNP has repeatedly said it would keep Labour “honest” and Nicola Sturgeon has claimed her party would be the “backbone and guts” of an Ed Miliband-led administration.
The official line from Labour is that Miliband is still capable of winning an outright majority. But it is well recognised that a deal with the Lib Dems, a party with representatives across the UK, would be far more palatable for Labour MPs than the alternative of being propped up by a party that wants to break up Britain.
Last night Angus Robertson, the SNP election campaign director, said: “The prospect of Westminster establishment parties getting together to impose more cuts will encourage even more people in Scotland to vote SNP.
“The more SNP MPs elected in May, the stronger Scotland’s voice at Westminster will be. SNP success can get the cuts planned by Labour, the Tories and Lib Dems reversed, in favour of modest increases in public spending to invest in jobs and services.”
Across the UK, Curtice’s poll-of-polls put Labour on 34 per cent ahead of the Conservatives on 32 per cent and heading for 262 seats compared with Labour’s 302.
The Lib Dems’ 20 seats would come from 9 per cent of the vote.
In Scotland, it still looks as though the SNP is set to make huge gains at the expense of Labour. SNP support was up to 44 per cent from 43 per cent last week. Labour support held steady on 27 per cent since last week. Curtice’s findings suggests that Labour is set to lose up to 30 or so of the 41 seats it won in 2010.
The poll-of-polls was published during a weekend of frantic campaigning that saw the Conservatives attempt to re-invigorate their campaign by promising an extra £8 billion for the NHS by the end of 2020.
Miliband campaigned on Labour’s offer of one-to-one midwife care for mothers-to-be.
The SNP stepped up its drive to win more traditional Labour voters with Sturgeon campaigning with people who have moved from Miliband’s party to the Nationalists.
Over the weekend, the SNP will deliver 2.4 million copies – one for every Scottish household – of a pocket manifesto for families.
The SNP cited the latest YouGov poll saying it showed that 41 per cent of people who voted Labour in 2010 now intend to vote SNP – a total of more than 400,000 people.
The former Labour MP Anne McGuire reacted to the SNP’s initiative saying: “Yet again the SNP arrogantly count votes before they are cast.”