A Grenfell Tower-style disaster could happen at the Palace of Westminster unless urgent repair work is done, the outgoing holder of the Black Rod parliamentary post has said.
David Leakey is standing down after seven years in the role as the senior official responsible for maintaining order at the House of Lords.
He insisted major action needs to be undertaken quickly to avoid a potential catastrophe.
With a full-scale overhaul of the Palace of Westminster estimated to cost up to £4.3 billion, Mr Leakey called on politicians to stop dragging things out and make a decision about what to do.
He told The House magazine: "I know what the risks are here. Knowing in detail that the expert recommendation is that you should do this quickly and now, not slowly over time in phases.
"I know that is necessary in order to prevent another Grenfell Tower happening here. And that's the point.
"If we don't learn the Grenfell lesson, this building could burn down, just like it did in 1834 when there was a decade of delay and procrastination about how or when to refurbish the building.
"We will again be accused of sitting on our hands.
"What an embarrassment and a disgrace it would be to our nation if our Parliament suddenly disintegrated in a puff of asbestos because the steam pipes burst in the cavities around this building and the electricity and the IT infrastructure went with them.
"There could be a major fire. There could be loss of life.
"The state of the fabric of this building is a red risk - the highest risk you can have in your risk register in terms of the likelihood of something happening, and of the impact of the consequences."
Mr Leakey said a "Grenfell dynamic" was making some politicians hesitant about spending huge sums of money of renovating Parliament.
"This is a national, global, iconic building. It has got to be either knocked down and rebuilt, or it has to be preserved because it is so iconic, and that is the decision that has been taken - the right one, I think.
"Speaking as a taxpayer, on that assumption, there is only one option, and that is doing it quickly and in the most economical way and that should be the end of the matter.
"The politicians have a more difficult problem. They will see it from the perspective of what is described as 'the Grenfell dynamic - if we couldn't spend a few million on the cladding of a residential tower block, why should we be spending billions - and it will be billions - on refurbishing the Parliament of this country?'
"This seems an unequal and disproportionate use of the taxpayers' money, and I really understand that Grenfell perspective and the dilemma in which the politicians find themselves too.
"So, here is the decision that politicians have got to take. They have got to find the courage to take a decision, the right decision, and stand by it, and justify it, and that will take some courage.
"Everybody probably has a finite pool of courage and you can exhaust your courage.
"I understand, therefore, that with so many tough current political issues on their plates, politicians need to pick carefully in which priorities to invest their courage."