MPs and peers have been told that they'll have to move out of the Houses of Parliament for six years or face double the bill for repairs.
If they move out, according to the leaked findings of a panel of experts, the work could be completed in six years, at a cost of £3 billion. If they stay, however, the cost would be £6 billion, and the work would take as much as 32 years to complete.
The Palace of Westminster has been neglected for decades. It's stuffed with asbestos, parts of the stonework are crumbling away, and it needs new plumbing and wiring. The roof leaks, and fire safety measures are inadequate. Maintenance costs £30 million a year.
A report due to be released later this week will examine three options for restoring the buildings to their former glory.
The cheapest and quickest is to move MPs and peers to the Methodist Central Hall on Parliament Square - their temporary home after bomb damage during the Second World War - or the nearby Queen Elizabeth II Conference Centre.
But many MPs are wary of this option, fearing that they'd never be allowed back in, and that the buildings would become a hotel or tourist attraction.
"Instinctively, I think it is important that this building remains consistently at the heart of our democracy and that we do not end up being forced to move somewhere else."
Staying put, meanwhile, would mean more than three decades of disruption, and cost twice as much.
A third, compromise option would see people decanted in batches, for example by clearing the House of Commons in one stage and the House of Lords in another. This, says the report, would mean the work could be carried out in about ten years.
There are also different options for the scale of the work, ranging from a bare-bones approach tackling only the most important issues to one involving making significant improvements.
A joint committee of MPs and peers is expected to be set up to examine the report, reaching a recommendation early next year on which plan to adopt. MPs and peers will then vote on whether to accept the plan.
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