According to Charles Moore writing in The Spectator, the Secretary of State for International Development Andrew Mitchell is intending to hang a portrait of his missus in the reception hall of his offices.

Moore wrote: “Mitchell ordered the flag be flown for Prince Philip’s 90th birthday and that a full-length portrait of his wife be hung.”

This seemed rather odd, until I realised suddenly that Moore’s reference was not to Mrs Mitchell but to Her Majesty The Queen.

‘His wife’ — is this really a proper way to speak of our monarch? I think not.

While The Queen herself famously uses the phrase “my husband and I”, I hardly imagine the Duke of Edinburgh would speak (in public at least) of “my wife”, still less of “’er indoors” or “the ball and chain”.

Maintaining a proper degree of respect when referring to royalty can quite often be a tricky business.

The late Princess Margaret, for instance, could be decidedly frosty with those who dared to “Margaret” her before she considered they had a right to. “Your Royal Highness to you,” she would snap.

It is also said that she began seriously to doubt whether Group Captain Peter Townsend would ‘do’ as a husband after he committed the faux pas of referring to King George VI as “your father”.