@ NJ Dubious? Hardly. Speculative, certainly. Loaded, certainly. Milliband has done nothing more than any other politician who favours keeping the Union has done.
And politics is about more than just numbers. Read this excerpt from a Constitution Society article; I am thinking Coalitions are likely to be much more common in our electoral future, personally, regardless of what happens with Scottish independence. I would hope the Scots vote to stay within the Union myself, but we shall have to see what they decide come referendum day.
"On the other hand, however, if the Scots voted ‘yes’, and at least one recent opinion poll suggests support for independence is growing,[3] it is felt in some circles that the Conservatives would be the principal benefiters among the UK parties because Labour is far more reliant on Scottish votes than the Tories are. Some have even gone so far as to suggest that the Conservatives would possess an in-built majority in England which Labour would struggle to overturn.
How convincing is such an argument? It is certainly true that the Conservative electoral strength is almost entirely concentrated in England. Of the 59 Scottish MPs who currently sit in Westminster, 41 of these are Labour seats, while only 1 is Conservative. In fact, one has to go back as far as 1955 to find an election in which the Tories won more seats in Scotland than Labour did.[4] Clearly, then, Labour would be at a much greater disadvantage than the Tories as a result of the loss of Scottish seats in the Westminster Parliament.
Nevertheless Labour is not as reliant on Scottish votes to gain an overall majority in the UK Parliament as these figures might suggest. Of the six Labour governments since 1945 only twice – in 1964 and February 1974 – was the party reliant on Scottish votes to help keep the Conservatives from office.[5]
The last three Labour governments in particular have all enjoyed comfortable overall majorities, which the loss of Scottish seats would not have overturned. In 1997 Labour’s majority was 178, of which only 56 were Scottish seats; in 2001 their majority was 166, of which 55 seats were Scottish; and in 2005 Labour’s majority was 65, of which 40 were Scottish seats.[6]
Nor does Labour’s recent electoral record in England suggest that the Tories would possess an innate advantage there. In 1997, for example, Labour obtained a majority in England alone of 127; in 2001 they had a majority there of 117; and in 2005 they secured a majority of 43.[7] True, in the 2010 General Election the Conservatives won 297 seats in England, compared to 191 obtained by Labour. [8] But this was off the back of thirteen years of Labour government, and the worst recession in living memory."
"http://www.consoc.org.uk/2012/02/would-the-conservatives-benefit-from-scottish-independence-michael-everett-constitution-society-researcher/