THERESA MAY was right to sack her Defence Secretary, Gavin Williamson, as she believes he was the source of the leak from the most sensitive security forum in the country. It was a surprisingly ruthless, and brutal, action by a politician who is renowned for kicking the can down the road to avoid decisions.

But equally, there is something very unsatisfactory about Mr Williamson being dismissed without the nature of the evidence against him being aired in public. Everyone deserves a defence – his reputation is in tatters even though he strenuously denies the leaking. That is not fair.

However, the rise of Mr Williamson – or “Private Pike”, as he was nicknamed at defence – must be another black mark against Mrs May’s judgement. He seems to be an expert on little more than political intrigue and ambition, and yet she put him in charge of the defence of the nation.

One of his speeches enraged the Chinese so that they cancelled an official visit; another of his statements was that Russia should "go away and should shut up”. He suggested to Polish counterparts that they could disguise missile systems as Coca Cola trucks, and he suggested that paintballs be fired at Spanish ships sailing too close to Gibraltar.

As it contains politicians of this calibre, it is little wonder that Mrs May’s Cabinet is regarded as one of the weakest in recent decades.

The one positive of this affair is that Rory Stewart, a sober, sensible-sounding fellow, has been promoted to the Cabinet. How we need some sober sense right now.