It is not bullying to show what Scottish independence means

Mr Salmond's has accused establishment forces of ganging up on him

David Cameron and his fellow cabinet ministers will descend on Aberdeen today in combative mood. Although the Prime Minister has refused to go head to head in a televised debate with Scotland’s First Minister, Alex Salmond, the long-distance argument over Scotland’s future has heated up this month.

In the space of little more than two weeks, the Scottish National Party (SNP) has been hit by a rare display of tripartite unity as George Osborne, Ed Balls and Danny Alexander all warned that an independent Scotland could not count on continuing to use sterling as its currency. The President of the European Commission, Jose Manuel Barroso, has warned that it would be “extremely difficult, if not impossible” for Scotland to remain in the EU.

There have also been warnings of the economic consequences of splitting from the UK from the heads of big businesses such as BP and Sainsbury’s. Mr Cameron’s latest line of attack is to warn that North Sea oil and gas – which the SNP sees as Scottish assets and its guarantee of continuing prosperity – will continue to need vast investment, which only a United Kingdom can supply.

Mr Salmond has reacted by accusing establishment bullies of ganging up on him and his party. That was a shrewd, calculated response from one of the UK’s smartest political operators. The first opinion poll after the Chancellor’s intervention on the subject of the pound suggested that it had backfired, leaving Scottish voters all the more inclined to tell southern politicians to get lost. More recent surveys, however, show undecided voters moving to the “no” camp while the pro-independence vote is static.

The important question is not whether an old political bruiser such as Mr Salmond is getting a fair hearing from Messrs Cameron, Osborne, Barroso et al. What matters is the welfare of the people of Scotland, and the rest of the UK. Almost everyone who speaks with any authority is warning that Scotland could be on the verge of taking a dangerous step. The Scots may feel sorry for an isolated Alex Salmond, but they would be unwise to follow him into isolation.