THE SNP hopes to capitalise on growing calls for reform of Westminster's voting system by pressing a minority Labour government to back proportional representation, it has emerged.
Senior SNP sources say they would link the party's manifesto vow to push for the single transferable vote system (STV) with a wider constitutional shake-up, including reform of the House of Lords, an aim shared by Labour.
Details of the plan emerged amid growing calls for Westminster's traditional first-past-the-post (FPTP) system to be changed.
The Electoral Reform Society, which campaigns for proportional representation, said the emergence of multi-party politics during the tightest election for a generation had exposed weaknesses with the old system.
Juliet Swann, campaigns officer with ERS Scotland, said parties would have to be clearer about potential post-election pacts, removing much of the speculation and "guesswork" which has dominated the election.
Lord Gus O'Donnell, the former cabinet secretary, has said the contest is likely to "raise questions" about FPTP, with Ukip and the Greens expected to win large numbers of votes across the UK without taking many seats.
The SNP backed STV despite being on course to do well from the present system.
Nicola Sturgeon's party is forecast to win about eight per cent of the Commons seats with four per cent of votes across the UK.
Ukip, by contrast, whose support is spread more thinly, is expected to take a tiny handful of the 650 seats at most, despite polling 14 per cent of the votes.
Under STV, the system used in Scottish council elections, seats are allocated in proportion to the votes a party wins.
An SNP source said: "We support STV in principle but we would see it as part of wider democratic reforms, including abolishing the House of Lords and replacing it with a fully elected second chamber.
"We would talk to other progressive parties about moving to proportional voting.
"This is another example, like ending austerity, where we need something bolder than Labour is prepared to offer."
Voters heavily rejected replacing traditional FPTP with a variant, the Alternative Vote system (AV), in a referendum in 2011.
Scots Labour leader Jim Murphy and Ruth Davidson, the leader of the Scottish Conservatives, reiterated their support for FPTP in Westminster elections during the final election TV debate.
Ms Davidson - whose party would stand to gain seats in Scotland under a proportional system - said she did not want to break the traditional link between an MP and the constituency they represented.
The Lib Dems and SNP have long supported proportional voting.
In their manifesto, the Nationalists say STV would "make sure every vote and every part of the country counts".
Campaigners believe the election with boost support for reform as a proportional system it would eliminate the need for tactical voting, which has emerged as a confusing consideration for many voters during the current campaign.
They also believe a system that would make hung parliaments the norm would force parties to discuss possible pacts and areas of co-operation openly as part of their campaigns.
Ms Swann said: "A year ago we never thought we would be here now, talking about voting reform so widely.
"It is a serious topic in this election.
"With the SNP, Lib Dems, Ukip and the Greens all talking about reform and Labour promising a constitutional convention, we hope we will at least have a conversation about this."
If the latest seat forecasts are correct, it may not be clear who will be the next prime minister for several days after the election.
David Cameron is expected to hold talks with the Lib Dems over the weekend if the Conservatives are the biggest party.
Labour may then enter talks with Nick Clegg's party early next week.
However, Mr Cameron has indicated he will press on until any hope of building support for his programme has gone, having claimed an administration formed by a second-placed Labour would not be viewed as legitimate.
It could take until next month before it is clear which party can command a Commons majority.
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules hereComments are closed on this article