AN EXTRA £18.6million is needed to repair the tower which houses Big Ben, according to a new estimate.
The increase has been blamed on the discovery of asbestos, pollution and extensive World War II bomb damage in the Elizabeth Tower, which houses the bell.
It means the renovation bill will rise from £61.1million to £79.7million.
Ian Ailles, director general of the House of Commons, said the works were proving ‘more complex than anticipated’, adding: ‘Understanding the full extent of the damage was impossible until scaffolding was up.’
But a spokesman for the House of Commons Commission said members were ‘extremely disappointed’.
‘It is very frustrating to learn that the project requires yet more funding,’ he added. The new budget will need to be approved by accounting officers of both houses in parliament.