She's wearing her heart on her cheek. Photographer: Jeremy Sutton-Hibbert/Getty Images
She's wearing her heart on her cheek. Photographer: Jeremy Sutton-Hibbert/Getty Images

Scotland is slip sliding closer to voting for independence in its Sept. 18 referendum. As the government in London realizes that the risk of a non-United Kingdom is growing, it needs to come up with a more persuasive argument than the promise of increased devolution to convince undecided voters that Britain is better together. Specifically, it needs to accentuate the positive.

A poll by TNS published today shows that each side of the debate won a percentage-point from the unsure in the past month; 42 percent would vote to remain in the U.K. and 30 percent would favor a break-up, resulting in an unchanged 12-point gap. TNS polled 996 people from April 23 to May 2; no margin of error was given.

Among those who said they will definitely vote, however, the yes-no gap shrank to nine points from 13 points a month ago; still in favor of Scotland staying with the U.K., but moving in the wrong direction if you are the Prime Minister of the United Kingdom of England, Scotland, Wales and Northern Ireland.

So David Cameron is considering granting increased powers to the Scottish parliament, perhaps regarding some kind of taxation control and a place on the foreign-policy stage, Bloomberg News reports today. Yet the tactic of granting a little more freedom in the hope that this will persuade Scots to forego full autonomy has proven demonstrably unsuccessful.

Devolving some controls over education, health, justice and environmental matters to Scotland from London in 1999 was supposed to quench the thirst for separation. Instead, it whetted the appetite of nationalists and led directly to Alex Salmond and his Scottish National Party winning the parliamentary majority that empowered it to demand a referendum.

To win the hearts and minds of those don't-yet-knows, the campaign against independence needs to stress what Scotland will gain from remaining in the U.K. rather than attempting to scare voters by banging on about the alleged downsides of flying solo. So far, that isn't happening. Cameron will have no-one to blame but himself if he ends up in the ignoble position of presiding over the loss of Scotland.

To contact the author of this article: Mark Gilbert at magilbert@bloomberg.net.

To contact the editor responsible for this article: Marc Champion at mchampion7@bloomberg.net