Unless the Tories dramatically improve their performance in the north, independence would most likely lead to further hung parliaments or small majorities for them or Labour.
History shows that after seven years at the top, politicians' ratings go into decline - and Cameron can't afford to lose votes in 2015.
Shadow Cabinet Office minister Jon Ashworth writes to Jeremy Heywood demanding to know how former Laura Wyld was appointed to the "politically impartial" post.
As the economy accelerates, it will become increasingly difficult for Osborne to defend the 1% cap on public sector pay rises.
When Cameron derides Miliband for not wanting to talking about the economy, he forgets that, for most voters, living standards are the economy.
It is not sufficient for Conservatives just to focus on reducing green taxes. We need to stop the corporate juggernaut and tax companies' excessive profits.
If this is a recovery, the voters will ask, why aren't we feeling it? Cameron and Osborne need to offer answers.
If they are to remain the largest party after 2015, the Conservatives need the Lib Dems to win back left-leaning voters in Tory-Labour marginals.
The Deputy PM vowed in his conference speech that the Lib Dems "will keep this government green" - and he meant it.
The balance of credit for getting the Tories even this far has clearly tilted towards the Chancellor.