MPs were turned away from the House of Commons chamber as water poured in through the ceiling because of a leak.
The sitting was delayed for an hour as numerous buckets near the green benches were catching drips raining in through the ceiling on Monday afternoon.
Staff were trying to keep the chamber dry, with protective coverings draped over the central table.
With the weather over Westminster exceedingly warm and dry, the cause of the leak was unclear.
But there have been repeated delays to plans to restore the crumbling Palace of Westminster, amid concerns of soaring costs.
A House of Commons spokesman said: “We are aware of a water leak on the estate and are taking urgent action to resolve it.”
Business in the chamber was scheduled to start at 2.30pm with prayers followed by work and pensions questions. The Commons authorities later confirmed a 3.30pm start time.
Labour MP Emma Hardy, who briefly walked into the Commons chamber before being turned away, said the water leak appears to be “just in front of the despatch box”.
The MP for Kingston upon Hull West and Hessle said: “I have just walked through and there are a lot of people working, around six or seven.
“Lots of blankets on the floor and a machine, which I’m not quite sure what is doing.
“It (the leak) is just in front of the despatch box, but the roof looks fine.”
Deputy Speaker Nigel Evans added: “Somebody has just said to me this is one leak where we don’t need an inquiry.”
In April 2019, water pouring into the Commons forced an abandonment of the sitting.
This occurred during a debate on tax matters and while proceedings carried on for a few minutes, the noise of water pouring into the press gallery soon became overwhelming.
