Is this the worst political metaphor ever?

Political wit is a tricky business and one of that discipline's subsets is especially difficult: the employment of a memorable metaphor or similie to illustrate a particular controversy.

In 1992, Dennis Skinner sought biblical inspiration for his assertion that sterling rejoining the ERM would be akin to 

"a dog returning to its vomit".

I seem to remember the leader of the then-MSF union, Roger Lyons, describe Michael Portillo's 1994 promotion to Secretary of State for Employment as 

"like putting Dracula in charge of a blood bank".

Simple points, well made. But cliches, even then. Which is perhaps why politicians attempt new comparisons in the search of that sharp piece of argument-closing rhetoric.

Do think it through first, though. Otherwise you end up, like Lib Dem Treasury Spokesman Lord Oakeshott, saying this sort of thing (of the appointment of Bob Diamond as Barclay's new Chief Executive):

"you don't put the chief croupier in charge of the casino".

Err. Yes, you do. A chief croupier's job is, amongst other things, to make sure that all the gambling is being carried out within the rules. He or she will understand risk, probabilities and financial irregularity better than most.

If anything, we should be encouraging career-changes from The Strip to the Square Mile.