As the Sun on Sunday dips almost 400,000, is the Mirror falling into the same trap?

As an ex-editor of a Sunday paper who started his career on what was far and away the world's biggest newspaper by audience penetration (the Sunday Post, read by 95% of the people in its main circulation area), you could say I have an axe to grind. And you would be right .

The axe is this: Sunday papers are different. And that difference, change of pace, exclusive stories that the dailies missed, (tracked down by reporters who relished in-house competition ) is what gave the axe its edge. It is why the Sunday papers usually sold more than their daily counterpart.

It is what helped me years later to take the Sunday Mail to its highest ever sales, over 900,000.

That is why I cannot understand the lemming-like rush by management to squish daily and Sunday titles together, demoralising and demotivating staff and removing from readers an extra incentive to buy.

You can make production economies without robbing a paper of its identity; you can source material from freelances if you have to cut the number of reporters.

Maybe Trinity Mirror , with all their current turmoil , haven't heard the latest circulation figures from the much boosted News of the World-Sun "reorganisation" into a seven-day operation.

The News of the World circulation in the month it closed almost a year ago was 2,667,428.

The April figure for the Sun on Sunday, despite massive promotion and a 50p price , is 2,297, 441. That's a loss of almost 400,000! What price progress?

It is simple (journalistic) common sense: no matter how fair-minded , the editor of two papers instead of one is necessarily conflicted. Which paper to favour with the big promotion or the expensive scoop?

I once had a great ( and expensive) footballing scoop plucked from my hands on the Sunday Mail by my "editor -in--chief " (an early management innovation) on the grounds that he didn't believe it. The story went to the Sun .

I am sure the joint editors are good and capable people . I know they will do their very best.

But it remains in my view a bad and ill-conceived idea. With one paper, one editor , you know he or she only has their own newspaper to focus on.

Thank goodness for the Daily Mail and the Mail on Sunday.