Repairing the crumbling the UK's Houses of Parliament could take as long as 40 years and cost taxpayers £7 billion if MPs refuse to temporarily decamp elsewhere, a report has concluded.

The report, commissioned by parliamentary officials and conducted by consultants led by Deloitte Real Estate, said the building has not undergone major restoration since 1950, NBC News reported.

It said "fundamental renovation can no longer be avoided" to protect a structure that is part of the "UK brand, instantly recognized and appreciated around the world."

"If it doesn't happen, we can't guarantee that this building will be here for future generations," Richard Ware, Parliament's director of restoration and renewal, told Sky News.

The report cited recent episodes including a burst pipe flooding the Committee Room Corridor and part of the ceiling in the Lords chamber falling onto the benches below, and said "the risk of a catastrophic failure is increasing."