DAVID Cairns is one of my closest friends in politics. He was also one of the most effective ministers I have ever known – astute judgment, common sense by the bucketful, impressive political instinct and extremely sharp and witty at the despatch box. He is also fiercely loyal; he’s never voted against the government or criticised it publicly.

I know that he loved being a minister, that he regarded it as an immense privilege, which of course it is.

And I know that until this morning he had no intention of resigning. But being named this morning by The Daily Telegraph as the Minister of State who was the subject of News 24’s report last night forced his hand.

When he says he is not part of a wider conspiracy to topple the prime minister, he is telling the truth.

David’s decision was one he reached with a huge amount of regret and he will be devastated. But it was also a decision based on honesty and principle and he deserves respect for what he has done, even from those of us who would have preferred him not to follow this particular course of action.