SDLP security stance is a reason to be wary of transferring to them

In five years 2011 to 2016 the force has spent £2 million on such people.

This statistic comes from a Freedom of Information Act query by the BBC. The Metropolitan Police in London spent more than £5 million on informers, and the total spend by police forces across the UK was almost £20 million.

It should be no surprise that Northern Ireland has the highest per capita expenditure. We still have a grave dissident terror threat. Weeks ago a PSNI officer was injured in a gun attack in north Belfast that could have easily killed him.

Northern Ireland also still has entrenched paramilitary crime, including by loyalist terror groups.

The SDLP seem to have been most outspoken in their concerns at this latest expenditure. This is no surprise: the party often tries to out-green Sinn Fein and for a long time it has expressed something approaching contempt for ‘spooks’.

The party might think that it is showing how vigilant it is against any possible British security over-reach by expressing such views. But the more moderate members of the party must know that use of informers in Northern Ireland has saved lives on a large scale. Even Sinn Fein has acknowledged that “police services around the world gather intelligence”.

The emergence of an opposition was a key development of the last Assembly, and a move towards normal politics and a step away from the absurdities of mandatory coalition.

Thus there is a logic to Mike Nesbitt saying he will transfer to SDLP before other unionists in the coming election. But that nationalist party, which recently could not bring itself even to back a Stormont motion saying that there is a problem with bail policy in Northern Ireland, despite the abscond of a dissident accused, perhaps has some distance to go in accepting rudimentary anti terrorist measures before being deserving of early unionist transfers.