The House of Commons sitting was suspended after water came pouring into the chamber, prompting calls for a leak inquiry.
Deputy Speaker Sir Lindsay Hoyle called a halt to proceedings after the leak started above the press gallery in the upper tier of the chamber.
MPs were distracted as they discussed their concerns about the loan charge when water began pouring from the ceiling.
Conservative former minister Justine Greening had been speaking when the leak began.
Proceedings carried on for a few minutes, but the noise of water pouring into the press gallery soon became overwhelming.
The chamber was suspended after MPs began looking nervously at the torrent from the old rafters above.
Conservative former minister Sir Peter Bottomley told the Press Association: “We will obviously need a leak inquiry.
“It demonstrates we must have restoration and renewal. But we are very grateful to the maintenance staff who keep this place going.”
Conservative MP Ross Thomson tweeted: “Not the first time there has been a leak in Parliament I’m sure.”
Labour MP Justin Madders tweeted: “In the Commons Chamber and can hear rain dripping in through the roof, Parliament really is broken.”
A House of Commons spokesman said: “We are aware of a water leak on the estate and we’re working urgently to resolve it.”