As we go to press (an important qualifier when the pace of events is fast and the stakes high), the diplomatic community of London is locked in a titanic struggle with the undiplomatic mayor of London. Should diplomats be required to pay London’s congestion charge on their automobiles, especially if the automobiles (or, more precisely, the occupants thereof) are engaged in official business? That is the pivotal question, and it is a matter of prestige, power, precedent, privilege and profit.

Why should the ambassador of Japan pay a fee to Ken Livingstone when, for example, he motors into London to deliver a protest note or aide-mémoire at the Foreign Office about the English abuse of sushi? After all, the ambassadorial vehicle is considered as inviolable as his embassy premises and