The roof of Parliament's newest building sprang a leak on Tuesday, forcing MPs to dodge drips of rainwater as heavy storms lashed Westminster.
Questions were being asked yesterday over the design of the £235 million Portcullis House, which opened in 2001, after the leak caused parts to be cordoned off.
Architects had to be called in to fix the roof in 2004, just three years after the building was opened and the latest problems have left some MPs unhappy.
"My house was built in the 1570s and the roof doesn't leak," Norman Baker, Liberal Democrat MP for Lewes told The Independent.
"Many people think the building looks attractive and I certainly agree that it's pretty, but the fact remains that it was too expensive and those in charge did not know what they were doing.
"The Commissioning process was not well handled. There are lessons to be learned here," he added.
MPs posted messages on the social networking site Twitter. Transport Minister Sadiq Khan wrote: "Just finished meeting in Portcullis House in Parliament, which was built in the late 1990s. The roof is leaking. Oh dear..."
A Parliamentary spokesman told The Independent that the roof of Portcullis House has a number of ventilation hatches fitted with high-tech rain sensors which close automatically when it starts to rain.
"The problem in this case was that the rain came on so quickly that the hatches didn't have time to close. There are three canteens below as well as several offices and seating areas, which got wet," said the source.
Parts of the country saw very heavy rainfall as the recent heatwave came to an end. Hastings was hit with three months-worth of rain in the heaviest downpour since records began in 1865. The Environment Agency issued flood warnings in East Sussex and along several rivers and their tributaries in southeast London.
The leaks are the latest in a series of problems with the building. A National Audit Office report in 2002 found 7,500 defects, including cracked glass panels in the courtyard roof and 300 loose door handles.
Hopkins Architects, who designed the building, had to advise Portcullis House on how to reapply the protective wax needed every four years for the building's distinctive bronze roof after it began leaking.
The corridor between the central lobby and the House of Lords also had to be closed off as the rain fell, forcing parts of the London transport system to close.
Tom Watson, a Labour MP and former aide to Gordon Brown, posted a message on Twitter reading: “Thunder storm creates chaos in Commons committee corridor."
Siôn Simon, Labour MP for Birmingham Erdington wrote: "The leaks are riduculous. They're massive. I got soaked by a committee corridor one."
A spokesman for Hopkins Architects refused to comment.