Leading article: Ring tone

Problems with Big Ben have always had an ability to set national alarm bells ringing. The prototype cracked in 1856 when it was being tested, prompting some to doubt that a bell strong enough for the largest clock tower in the world could ever be made.

When two Greenpeace activists scaled the tower that houses the 13-ton bell two years ago there was outrage that that a national icon had been defiled. And what was the spectacular scene used to publicise a recent film? The destruction of Big Ben, of course.

So readers will understand why news that the four quarter bells that accompany Big Ben will not be sounding have prompted more public interest than most announcements of maintenance work around the Palace of Westminster.

These are the bells that have been broadcast live around the world by the BBC since 31 December 1923. Legend has it that if the ravens were to leave the Tower of London Britain would fall. Surely the next omen of disaster would be Big Ben falling silent.

True, there have been moments of silence in the past. When the clock broke down in 1976, it was almost a year before it was reactivated. And last October it fell silent for 33 hours. But this time, the Palace authorities are being worryingly vague about how long the chimes will be out of action.

As the Keeper of the Great Clock points out, there is no "How to repair Big Ben" textbook. More is the pity. From today we will not be asking "for whom the bell tolls", but "when".