So Alex Salmond wants 20 MPs beyond the General Election.
His logic: win 13 extra seats and, in the event of a hung Westminster parliament, the Nationalists would have the whip-hand in future negotiations.
The result: concessions for Scotland; including perhaps previously retained money for renewable energy projects and a longer term payment plan for the replacement Forth Crossing.
Such an outcome can’t be ruled out, but it’s also far from a political certainty - not least as it ignores the role of the Liberal Democrats under such circumstances.
Let’s consider another - perhaps more likely - outcome: a Conservative majority. What could a block of 20 SNP MPs, if secured, hope to achieve?
The Nationalists would focus heavily on the perceived legitimacy-gap of a Cameron Government – which is unlikely to secure more than a handful of Scottish seats. The approach would be: how can a party rejected by Scottish voters truly claim to govern them?
We’ve been here before. In 1987 Margaret Thatcher won a majority of 102, but claimed just 10 seats in Scotland – 50 per cent fewer than four year’s earlier.
In contrast, having claimed 50 Scottish seats, Labour had a strong case to ‘speak for Scotland’. But even then Donald Dewar envisaged significant risk in Labour’s position.
Shortly after the election he warned his party must achieve tangible successes in defending Scotland from Mrs Thatcher to ward off the Nationalist threat.
In a Fabian pamphlet he wrote: "Can Labour deliver? Can the fifty MPs protect Scotland from Mrs Thatcher? Can the poll tax be stopped? Can Labour setup the assembly?"
He added: "If the answers are in the negative the Nationalists will be there to draw some very uncomfortable conclusions…. Scotland went overwhelmingly for Labour and the reward, or the argument runs, is a continuing dominating Tory Majority."
In the end Labour’s Scottish MPs could do little to halt Thatcherisim in Scotland and, as Mr Dewar predicted, the SNP were soon branding them the "Feeble Fifty".
David Cameron can only dream about such a large majority, but it’s a lesson the Nationalists must learn, or they risk being dubbed the "trivial twenty". As experienced political 'guerrilla fighters', a block of 20 Nationalist MPs would undoubtedly seek to ‘harry’ the Tories for a better deal for Scotland. They may even land the odd punch or two.
But in reality would the SNP be in any stronger a position than their Scottish Labour counterparts two decades ago to influence a Tory Government flush with new power?
Mr Cameron accepts his party’s unlikely to win a mandate from Scotland; he’s promised to govern north of the border "with respect". But if Mr Cameron fails to deliver on his promise, the SNP now has a powerful advantage over the 'Feeble Fifty': devolution.
Just a year after the General Election looms a Scottish election. Any suggestion of Scotland getting a raw deal from Westminster will be a gift to the SNP, something Scottish Tory leader Annabel Goldie must fear.
It's a short-term trap Mr Cameron will surely avoid but the real test for both him, and an enlarged SNP block, would come in the period after the 2011 Holyrood election.
Can the SNP achieve real policy concessions from a Tory Government focused elsewhere? Only then would we know if a block of twenty SNP members proves terrific, tenacious or merely trivial.
Last updated: 05 November 2009, 17:05
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