A football sized chunk of masonry has broken away from a stone angel on parliament’s Victoria Tower and plummeted 230ft (70m) to the ground.
The chunk of stone missed pedestrians but police cordoned off an entrance to the Houses of Parliament and the garden beside it as a safety measure.
In October, an MP’s car windscreen was smashed when a piece of masonry fell from a building.
A sculpture of an angel has a piece missing after it became loose and fell. Black Rod’s Entrance and Garden have been closed after a chunk of masonry fell from Victoria Tower at Parliament
Part of a sculpture of an angel (circled) became loose and fell from Victoria Tower
Graphic shows the proposed renovations of parliament
The car belonged to Tory MP Michael Ellis but colleagues said accident showed why Parliament needs urgent repairs.
The Palace of Westminster is in line for a major renovation expected to cost up to £3.9billion, but so far MPs have failed to reach a consensus on whether they should move out while the work is done.
Tory MP Will Quince tweeted a photo showing the smashed windscreen of a Toyota Prius, with the caption: ‘Evidence of why Parliament needs urgent repair. This stone fell off the top of a building.
‘Imagine if this had hit someone.’ He later removed the picture, saying he had been instructed to do so ‘for security reasons’.
He added: ‘I appreciate the picture is embarrassing to the parliamentary authorities given how serious this could have been.’
A parliamentary spokesman said the main entrance to the building had been closed until further notice and the incident was being investigated urgently.
Work is being carried out to repair the Elizabeth Tower, which famously houses Big Ben and the iconic landmark clock it houses.
Conservation workers and Palace of Westminster Staff look up to inspect the damage after part of a sculpture of an angel became loose and fell from Victoria Tower
The Houses of Parliament, pictured, is in line for a major renovation expected to cost up to £3.9billion, but so far MPs have failed to reach a consensus on whether they should move out while the work is done
In January, it was announced the future of the Palace of Westminster will be voted on by MPs but a final decision on a multibillion-pound restoration programme could be further delayed.
Parts of the Houses of Parliament are crumbling and there have been warnings that a catastrophic fire could occur unless ageing electrical systems are replaced.
But concerns over cost and public opinion have dogged the restoration and renewal project, expected to cost around £4 billion, and one of the options put forward for MPs to consider is for a further review.