IT is the most famous bell in the world - first forged in North Yorkshire - and which has heralded in the New Year for more than one and half centuries.
However now the taxpayer faces a bill of up to £40 million to keep the famous “bongs” of Big Ben sounding, according to a report.
Parliament’s Great Clock is said to be so dilapidated that it could grind to a halt unless drastic repairs are carried out to the landmark which was completed in 1859.
Officials say the three-year restoration programme needs to start as soon as possible and cannot wait until the eyewateringly expensive (up to £7billion) refit of the crumbling Palaces of Westminster starts at the end of the decade.
A report presented to the cross-party Commons Finance Committee has set out a £29.2 million plan for fixing the issues on the clock, whose movement has been famous for its reliability, but is now said to be struggling to keep time.
It would see the mechanism shut down for four months - believed to be the longest stoppage in its 156-year history.
The document said: “The clock currently has chronic problems with the bearings behind the hands and the pendulum.
“Either could become acute at any time, causing the clock to stop - or worse.”
Action is also needed to combat “severe metal erosion, cracks in the roof and other structural defects” in the Elizabeth Tower.
“There are major concerns that if this is not carried out within the next two to three years, the clock mechanism is at risk of failure with the huge risk of international reputational damage for Parliament,” the report said.
“In the event of a clock-hand failure, it could take up to a year to repair due to the scaffolding needed.”
The proposed £29 million “full refurbishment” would involve the clock being stopped for four months, and each of the four faces covered in turn as work was undertaken.
A visitor centre would be constructed at the foot of the 315ft tower and a lift installed as an alternative to the 334 steps. The previous longest shutdown is thought to have been in 1976, when the clock stopped intermittently for 26 days over nine months while repairs were carried out.
Officials admit it would cost only £4.9 million “to prevent the clock from failing”, but they suggested the cost could rise to a cumulative total of £40 million if the underlying problems are not dealt with in one go.
Big Ben is the nickname for the Clock Tower, but is properly the name of the 13.5 tonne bell it houses.
John Warner & Sons of Stockton built it originally, and it was transported amid cheering crowds to the Tower on a trolley drawn by 16 horses.
But it subsequently had to be recast after cracks appeared.
Parliament had a special sitting when the Great Bell first rang out in 1859 to decide a name.
Legend has it that at the end of an impressively long speech by Sir Benjamin Hall, a large, ponderous man known affectionately as “Big Ben”, a wag chipped in: “Why not call him Big Ben and have done with it?”
While his name is inscribed on the bell, the remark is not recorded in Hansard and it has also been suggested that it actually alluded to bare-knuckle champion boxer Benjamin Caunt, who at one stage topped the scales at 17 stone and was known as the “Torkard Giant” and “Big Ben”