Members of the public have been banned from the Commons chamber after a hidden phone was found during a security sweep shortly before Prime Minister’s Questions (PMQs) on Wednesday.
Tourists and visitors will be unable to walk among the green benches “until further notice” while an investigation takes place, parliamentary authorities have said.
The ban also applies to the House of Lords chamber, but other areas of Parliament will remain open.
It comes after a mobile phone was discovered in the lower chamber, with media reports suggesting the device had been planted to play sex noises as a prank during PMQs.
Scotland Yard has launched a probe and said it believes the phone was “purposely” placed there “with the aim of causing disruption to business in the House”.

The Times reported that the phone had been hidden near the front bench to broadcast adult content in the middle of Sir Keir Starmer’s weekly showdown with Kemi Badenoch.
A UK Parliament spokesperson said: “While investigations continue, we have decided to temporarily limit full public tours in both Chambers from Saturday September 6, until further notice.
“Public access to the rest of Parliament is unaffected and remains open as usual.
“We have robust and proactive security measures in place in Parliament and the safety and security of everyone who works or visits here remains our top priority.”
A source earlier told The Times: “It looks like it was just a prank, but it could have been much worse.”
And they raised concerns that it could have been an explosive, adding that “we don’t know how it got here”.
Multiple live events have been disrupted by “sex noise” pranks in recent years, though the victims have mostly been sport-related.
The Euro 2024 draw was hit as pornography sounds were loudly played as teams were finding out their groups for last summer’s football tournament.
Social media personality Daniel Jarvis, known as ‘Jarvo69’, promptly claimed responsibility for the prank, declaring on a live stream: “We done it, we got in there. Sex noises at the Euro 2024 draw. Love you guys.”