UNTIL now, the story has been the traditional narrative of debating, canvassing, handing out leaflets and opinion polls.

There will be a referendum and if the people of Scotland vote Yes to independence then it will happen a couple of years later.

It has been agreed, both Governments will abide by the outcome. We saw the pictures of First Minister Alex Salmond and Prime Minister David Cameron shake hands, all we need to do now is wait for the people to decide.

Except what we are talking about is the break-up of one of the world's most successful unions and one with a State apparatus that can reach not only into every corner of its own territory but deep into the affairs of others to protect its interests.

This week the big referendum story is the leaked confidential Scottish Cabinet paper on the volatility of oil revenues and the affordability of public services.

Where did it come from? How did it get into the public domain?

Well, that is the intrigue.

Scottish Government officials may say there is no leak hunt, but they are certainly interested in how it came about.

The document is a year old, so what that says about the validity and relevance of its contents is up to whoever reads it. But the timing and route from private to public is more interesting.

It was leaked to coincide with official figures showing Scotland's economy was doing better than the UK as a whole.

So was someone sitting on the paper waiting for the best time to put it in the public domain and, if so, who?

Well, if the UK Government can have people in place in departments around the world supplying otherwise confidential information back to London, you don't need to be Ian Fleming to think there will also be people in Edinburgh.

With still more than one year to go before the vote, both sides are still stating they want this to be a positive debate and fairness will carry the day. To believe that is to ignore what is at stake.

Far fetched?

Well, politics through the ages has seen dirty tricks and betrayal, and there is no reason to believe the Scottish independence referendum will be any different.

Much of it will not come to light, but to think there is an honourable agreement signed between Mr Salmond and Mr Cameron and that all will be above board and may the best man win is to ignore the prize.

Make no mistake: behind the scenes, the spirit of 16th century mover and shaker and manipulator Niccolo Machiavelli will be alive and well, if not that of 20th century fictional character Commander James Bond.

Things could be about to get dirty.