Restoration work on the Houses of Parliament could cost as much as 5.7 billion pounds and take 32 years to complete. However, the hefty price tag could drop to 3.5 billion pounds if MPs and peers are moved out of the building.
The 150 year-old Grade I listed property is partly sinking, contains asbestos and has out of date wiring. An independent report found other problems including crumbling stonework, leaking roofs and failing plumbing.
The Palace of Westminster was rebuilt on the banks of the River Thames in the mid-1800s following a fire. Many of its features have never undergone major renovation since. A world heritage site, the building incorporates the tower of Big Ben and the oldest building on the site, Westminster Hall.
The report warns the building could suffer "major, irreversible damage" without significant restoration work. Listing five solutions, the cheapest option would involve moving parliamentarians out of the building entirely for six years. Some MPs have welcomed the idea.
"I think we've got to be pragmatic and practical. Whatever is the most sensible solution to preserving the historic heritage that we have, not just for the sake of MPs who work here, or members of the House of Lords or the staff but just for the country because it's such an iconic building.”
But others insist they should remain in Westminster.
"My view is that we should seek to avoid moving away from here. We need to stay in the heart of Westminster where our democracy is based. But of course we've got to do it in the way that makes it possible to get the job done.”
The Commons and Lords will have to vote within the next few years on what to do to solve their potential housing problem.