MPs say no repairs will be done on Big Ben before 2020

Renovation work on the Palace of Westminster will not begin until at least 2020, an MPs' committee has said.

The decision came after surveyors found that Parliament's Clock Tower - better known as Big Ben - was leaning.

The House of Commons Commission said officials would conduct an investigation into how repairs could be carried out, but no decisions would be taken until the next Parliament.

But it stressed that the Palace remained "structurally sound".

The Clock Tower, housing the bell which is called Big Ben, was completed in 1859.

Since then a five-storey car park and the Jubilee underground line have been constructed.

Cracking

In October, Prof John Burland, a construction expert from Imperial College London who oversaw the building of the car park, said the tower was leaning, but it would not be a major concern for at least 10,000 years.

The Palace of Westminster is also suffering from cracking.

Prof Burland told the BBC on Monday the tower was "moving incredibly slowly and always has done so and there really is no immediate danger at all".

He added: "There's no such thing as an old building that isn't cracked. In fact they're beneficial because the building moves thermally more than is caused by the Jubilee Line and the movements concentrated around the cracks and, if they didn't, there'd be cracking elsewhere."

At its monthly meeting, the House of Commons Commission agreed that officials from both Houses should conduct an initial study, lasting about a year, into the necessary renovations.

Any subsequent work agreed upon after the next general election in 2015 would not begin before 2020 at the earliest.

It said in a statement: "The commission also wished to state that, contrary to some recent speculation, the Palace of Westminster remains structurally sound and that while the Clock Tower (commonly referred to as Big Ben) has a very slight tilt, this is not causing structural problems and has not changed since the statement made in October."

Tower of Pisa

It is not the first time there have been problems with Big Ben, which stands at 96m (315ft) tall.

In 1976 pendulum weights fell down a shaft and the clock mechanism exploded, putting it out of action for almost nine months.

Although the tilt is nothing like as pronounced as that of the famous Leaning Tower of Pisa in Italy, it can still be spotted by the naked eye - just.

Prof Burland said: "If you stand in Parliament Square and look towards it, you can just see that it moves very slightly to the left, but I wouldn't put any political slant on that."

He added: "I calculated that it would take 10,000 years to reach the inclination of the Leaning Tower of Pisa."

In the Commons on Monday, Conservative MP Robert Halfon raised a point of order asking "whether or not to buy our life jackets" because Parliament may be sinking into the Thames.

In reply, Speaker John Bercow said: "I have never regarded you as an inveterate worrier. As you can see, I am not worried."