"They fear a General Election win for David Cameron could drive voters into the SNP's hands as the Nationalists would be seen as the "lesser of two evils".We became used to hearing this line about a 'mandate to govern Scotland' under Thatcher and perhaps even more so under Major. Despite not being a fan of Conservative rule, this line used to really annoy me - and it makes even less sense now that we devolution: parties seeking election to Westminster need a mandate to govern Britain; they don't need a separate one for Scotland, or for Wales.
SNP figures admit privately that a Tory victory would be good for their cause, allowing them to accuse Mr Cameron of having no mandate to govern in Scotland, [emphasis added] where the Tories admit they are unlikely to add many – if any – seats. There is only one Tory MP in Scotland at present."
That people can, post-devolution, argue the contrary illustrates how far the nationalist logic has taken hold. Scottish Labour have to take their share of the blame for this - and my own view is that this share is large, since they were inclined to play this 'Scottish mandate' card when they were in opposition.
It would be hypocritical in the extreme for Labour to complain about the Tories playing the English nationalist card - but I doubt that this would stop them. A threat to the union greater than the voting behaviour of Scots would be if the Tories decided that to maintain it was simply no longer in their interests. This logic has not been lost on some English Tories. I don't think it's lost on the present leadership either. I would, despite myself, be inclined to say that it reflects reasonably well on Cameron that, despite this understanding, he has more or less resisted this - but we'll see if this remains the case in the future.