British taxpayers may have to cough up £3bn worth of repairs, to stop parliament falling into "ruin" because the Palace of Westminster has not been updated since the 1950s.
According to a Newsnight investigation, a senior parliamentary insider said the renovations could be "embarrassing, expensive and difficult".
Project director Richard Ware said restoration and renewal work was urgent as parliament was "sinking and crumbling".
"We're moving backwards. The building is getting older, faster than we can deal with it," said Ware to Newsnight.
"The building is on borrowed time and, if we don't act soon, we won't have a choice. [Staff and politicians could end up working] in a ruin."
Parliament has an annual upkeep bill of around £30m (€37.5m, $47m) as its riddled with Avesta, crumbling facades, leaking pipes and damage incurred from fires and flooding.
According to the report, authorities are considering moving politicians and staff out in five years, due to the level of costly repairs.