The gift of speedy repartee is given to few, which is why the French invented that serviceable phrase ‘esprit de l’escalier’ — the crushing retort that comes into the mind after one has been chucked down the stairs and which, delivered smartly, would have crushed the enemy under a mass of ridicule.

It was always unwise to tangle with George Bernard Shaw, for example.

He once encountered a very fat man lumbering up a narrow staircase and, being in a hurry, pushed past him. “Pig!” said the fat man.

Shaw raised his hat politely and said: “Shaw. Good afternoon.”

Dorothy Parker had the gift in abundance. She and society queen bee Claire Booth Luce conducted a life-long feud and Dorothy’s waspish wit was guaranteed to keep the humourless Claire seething.

They once arrived at a social event at the same time; Claire stood aside for Dorothy to enter, saying “Age before beauty.” As Dorothy swept past her, she replied “And pearls before swine.”

Those who challenged Winston Churchill rarely came off best. As he was speaking one night in parliament, Bessie Braddock, a very large lady member of the opposition, called across the chamber: “Mr Churchill, you are drunk.”

Churchill riposted: “Madam, you are ugly — but I shall be sober in the morning.”

There is some doubt as to whether it was the eighteenth-century radical John Wilkes or the English playwright Samuel Foote who routed the crusty, dissipated Lord Sandwich in this exchange:

“I think that you must either die of the pox or the halter.”

“My lord, that will depend upon one of two contingencies — whether I embrace your lordship’s mistress or your lordship’s principles.”

In Australia, the bumptious and inexplicably dislikeable conservative politician Peter Costello was known for caustic wit. He once twitted the secular saint, Senator Bob Brown, that the Greens party he leads is like a watermelon — green outside but red inside.

The Senator rose to the challenge and said the Greens were actually like an avocado, green inside as well as outside. Costello pounced at once: “Yes, true — and with a big Brown nut in the middle.”

And there is the perhaps aprocryphal Australian parliamentary anecdote about a politician who opened a speech with the words “I’m a country member…” only to face a roar from the opposition benches of “We remember, we remember.”