Live news viewers spot Big Ben running slowly

Refurbishment work on Big Ben caused the clock to run nearly half an hour slow yesterday.

An electronic motor has been installed to drive the hands of the clock in the Elizabeth Tower while its existing mechanism was dismantled, but due to a power cut the South Dial stopped working.

The error was spotted by eagle-eyed viewers of BBC News, who saw the clock showing the wrong time in the background of a live broadcast. A Commons spokesman said mechanics have since fixed the issue.

The last time Big Ben displayed a time delay was in August 2015, when it was running six seconds slow.