How popular will the SNP manifesto be?

Last weekend, the SNP launched its latest campaign slogan. "My vow is to make Scotland stronger at Westminster," promises a poster that has begun to appear on expensive billboards across the country. Beside the pledge a smiling Nicola Sturgeon stands, her arms folded.

The pose is both hospitable and formidable, the message unambiguous: Scottish nationalists are the only politicians who can really stand up for Scotland in London.

This theme—that only the SNP can effectively represent Scotland in the "Imperial capital"—runs through the party's general election manifesto. The 38-page document promises to deliver plenty for Scottish voters, and a little bit for those in the rest of the UK too, if the SNP find themselves with a meaningful say in Westminster after May 7th. But how popular will it be? And what does it say about Scotland's future?

Launching the manifesto, Sturgeon was as composed and as impressive as she had been in recent TV debates. Scotland’s first minister promised to "end austerity", which translates as modest real terms spending increases of 0.5 per cent a year. It's hardly a great Keynesian revolution but in a general election where all three main Westminster parties are agreed on the need to reduce to the deficit quickly, the nationalists' open calls for more public spending strike a bold tone.

Less voluble is the party’s commitment to independence. Although the “I” word received a great cheer among the Edinburgh audience, there is just a single substantive reference to leaving the UK in the manifesto—and that is a pledge that independence is “not what this election is about.”

One word that does appear frequently in the nationalists’ manifesto is “progressive”. The SNP has pledged to form a “progressive alliance” in Westminster with the Greens and Plaid Cymru ostensibly, as Sturgeon has said many times in recent weeks, to “make Labour bolder.” In Scotland the idea that the nationalists can push Ed Miliband leftward has gained traction. Even allowing for a late swing to incumbents, Labour is set for heavy losses in its Scottish heartlands come May 7. In England, the Lib Dems and, in particular, the Tories have gleefully depicted nightmare visions of nationalists in government in an effort to woo swing voters away from Labour.

So how far to the left of Labour is the SNP? The answer is not all that much. The SNP will back a 50p top rate of tax, a mansion tax and a levy on bankers' bonuses. The party will also match Labour on NHS spending and "zero hours contracts" and abolish the bedroom tax. The minimum wage would be increased to £8.70 an hour. But the SNP does not have to be significantly to the left of Labour to pick up Labour seats—polling suggests that former Labour voters that intend to switch to the SNP next month are among those least likely to change their minds.

Ahead of its launch, SNP press officers hailed the manifesto as an attempt to reach out to voters across the UK for arguably the first time. Trident will be scrapped—freeing up a predicted £100bn—and the party would like to see more infrastructure spending in northern England. Both policies will find receptive ears south of the border. The commitment to vote on the English NHS, however, is likely to fuel further English fears about nationalists in government. There is little in this manifesto to assuage the concerns of non-progressive voters in the rest of the UK. Indeed SNP MPs would vote to prevent a Conservative government “getting off the ground.”

Another referendum is still a long way off. The SNP will not go to the polls again until they know they can win—ten years is a more likely timescale than two, although a vote to leave the EU could speed things up considerably. Retaining control of the Scottish Parliament next year remains Sturgeon's main focus. The SNP manifesto reads at times like the opening gambit in these potential post-election negotiations. Talk of fairness and burdens falling on those with the broadest shoulders will create even more headaches for Scottish Labour. The right-wing press will seize on the refusal to rule out another referendum and commitments to more spending as further proof that the SNP are dangerous lefties hellbent on breaking up Britain. The SNP, and Nicola Sturgeon, will just keep smiling.