As the referendum campaign bowls on, England is today the chosen arena for both Alex Salmond and David Cameron.

The Prime Minister will use his St George's Day speech in London not only to talk up Newcastle Brown ale, Cornish pasties and other quintessentially English brands but also to proclaim England's role in "the world's greatest family of nations", adding that "no matter how great we are alone, we will always be greater together", a message aimed at Scottish as well as English audiences.

He does so as the First Minister ventures south to Carlisle to inform local business leaders there (and by extension on the Scottish side of the border) that trade would continue to flourish between the two countries if Scotland became independent.

Loading article content

There is no question that the pro-UK side is facing the greatest challenge in the campaign as a whole, having watched the polls narrow. Mutterings of discontent about the Better Together leadership of Alistair Darling from one Conservative source is not only somewhat unfair, but also another own goal from the undisciplined peripheries of the campaign. Still, the Prime Minister's heartfelt case for the UK seems designed to rise above all that and answer calls for more positivity. His speech will reinforce the view that the UK is a precious entity drawing strength from its diversity, a message that is upbeat and uncontroversial.

In fact, it is Mr Salmond who is today on trickier ground, going to the north of England on a mission of reassurance about the potential impact of independence on cross-border trade. Talking up the neighbourliness and long-standing links between England and Scotland, Mr Salmond will insist that the pound would be shared between an independent Scotland and the rest of the UK, swatting aside the declaration of all the UK's main parties that it would not, and that it will be business as usual for cross-border trade. Yet he will also propose a series of "special borderlands economic forums" in the event of a Yes vote as a "practical demonstration of co-operation and partnership between us".

It may prove difficult even for a politician as skilled as the First Minister to convince business people that doing trade with a different country, with potentially different bureaucratic requirements and uncertain currency arrangements, would be as straightforward and risk-free as trading with firms in the same nation. The perceived need for borderlands economic forums after a Yes vote would tend to underline the fact that circumstances would indeed change and need an extra level of oversight. The view of Carlisle MP John Stevenson that the UK provides a strong framework for flourishing trade between Scotland and England, and that Scotland leaving would only complicate matters, is likely to be one instinctively shared by many businesses, on both sides of the border. Mr Salmond will have his work cut out to convince them otherwise.

No bloody battles or dead beasts are in prospect, then, far less any saintly heroes, but a meaningful St George's Day all the same.