Jim Armitage: Sainsbury's boss Mike Coupe called the merger so badly wrong he must go

IF YOU believe Sainsbury’s, nothing in today’s decision from the competition regulator changes anything. We knew the watchdogs didn’t like the merger from the start, so this was merely a confirmation.

Wrong. In fact, it was widely seen as more likely that the regulator would offer some concessions today. These would be totally unacceptable, killing off the whole rationale of the deal, but concessions nonetheless, showing that at least the regulator was willing to talk.

Instead, the door to the merger was slammed shut, triple-locked, and chained to a snarling guard dog.

So, even more than we thought, the Competition and Markets Authority truly hated this deal.

Which is why today’s decision is terrible news for its architect, Sainsbury’s chief Mike Coupe.

He championed this deal with all the energy he could muster. He declared it the oxygen for his company’s future growth. Now it has been so comprehensively rejected, his position looks untenable.

Blame the competition advisers all you like (Linklaters for Sainsbury, Gibson Dunn for Asda), but it’s the chief executive who makes the decision.

Was the CMA right? Doesn’t matter; CEOs are paid millions of pounds a year to get the big calls right, and Coupe called it wrong. He has to go.

It won’t happen quickly. Don’t expect new chairman Martin Scicluna to serve up his head with next week’s profits announcement.

But, quietly, expect the succession search to start.

Luckily, there’s not too far to look. John Rogers, who has successfully integrated Argos, would be a fine replacement.

He didn’t throw his hat in the ring last time the job came available, presumably feeling he lacked the experience. This time he shouldn’t be so coy.

Everywhere you look, vacancies are coming up for the top dogs.

The Bank of England, Reckitt, BAT, GVC, Imperial Brands are all looking for new CEOs, chairmen or governors.