Why identikit lines on the SNP are important for the Tories

This morning when George Osborne defended the way the Tories were fighting the election campaign, there was something slightly odd about what he said in response to John Humphrys’ first question:

‘We’re two weeks to go to this election and it’s coming down to a very clear choice on the economy, and on 8 May we can either get straight back to work with a clear plan that is delivering for our country or we face this deeply unstable Miliband/SNP government committed to much more borrowing, and that leads to a dangerous cocktail which increasingly, international investors say will lead to higher mortgage rates, higher taxes and lost jobs, and we have got to avoid that outcome having achieved so much in Britain over the last five years.’