BIG BEN'S bongs have been six seconds out for the past fortnight, parliament's clocksmiths have admitted.

It is not known what caused the 156-year-old Great Clock to go so disastrously wrong, although it does have a reputation for being "temperamental".

The inaccuracy was discovered over the weekend of August 15 and 16 when BBC producers who use the chimes live noticed it crashing into their headlines.

The clocksmiths have gradually wound down the error and now it is back to its usual margin of being less than one second wrong.