Parliamentary authorities have refused to reveal how much porn MPs and their staff are trying to look at on work computers, citing "national security".
The refusal to disclose the information under the freedom of information act comes after Tory MP Neil Parish quit as an MP after he was caught looking at pornography at work in a "moment of madness".
But ahead of the by-election to replace Mr Parish later this month authorities rejected a freedom of information request by The Independent, citing Section 24(1) of Act.
Section 24 says says information does not have to be disclosed if secrecy is "required for the purpose of safeguarding national security".
The refusal is a change in policy for the Commons, which has previously disclosed how many porn sites were blocked on work computers on at least three separate occasions.
Recommended Labour MP asks Boris Johnson how country can trust him if 148 Tory backbenchers don’t Inside Politics: A Frosty intervention Boris Johnson warned he has until the autumn to save his premiership
In 2013 parliament disclosed under FOI that computers on the parliamentary network had been blocked trying to access explicit content 309,316 times in the previous year.
In 2015 a similar disclosure revealed nearly 250,000 requests, and in 2018 the figure had fallen around 24,000.
But the Commons authorities told The Independent that it had not only blocked the latest FOI request, but retroactively deleted the previous disclosures from its website.
As well as the national security exemption authorities cited Section 31(1)(a) and (b), which says information can be exempted if required for "the prevention or detection of crime" and "the apprehension or prosecution of offenders".
In its FOI response letter authorities accepted that there was "a legitimate public interest in the House of Commons being open and transparent" but that "disclosure of this information would cause substantial risks to the parliamentary network as it would aid malicious groups in their efforts to target the network" as "both the disclosure of either specific web addresses, categories that are blocked, or totals relating to attempts or access, could provide valuable information to those wishing to bypass our security systems".
This is because releasing the data "would make the extent of the Parliamentary Network’s blocking and filtering policies public knowledge".
Maurice Frankel, director of the Campaign for Freedom of Information, told The Independent that the block appeared to be part of wider pattern.
"It seems that guidance has been issued to public authorities advising them not to release details of their monitoring of internet usage for fear of helping criminal, malicious or hostile users target these systems," he said.
"Given past disclosures that hundreds of thousands of attempts to access pornographic websites have been made annually from Parliament its impossible to believe that hostile users don’t know this, particularly after an MP was found accessing pornography while actually in the Commons chamber."
UK news in pictures Show all 50
1/50UK news in pictures
UK news in pictures 9 June 2022 A traveller rides a horse in the River Eden at the Appleby Horse Fair, the annual gathering of gypsies and travellers in Appleby, Cumbria
PA
UK news in pictures 8 June 2022 An activist from Extinction Rebellion holds a dog wearing a construction helmet as they attend a protest during a biodiversity conference being held at Dublin Castle, calling for legal protection for Ireland’s wildlife
Reuters
UK news in pictures 7 June 2022 Downing Street staff take down Jubilee bunting outside 10 Downing Street in London. British Prime Minister Boris Johnson has survived a “vote of no confidence” over his leadership but has lost over forty percent of support from his MP’s following the vote at parliament
EPA
UK news in pictures 6 June 2022 Gannets gathered at Bempton Cliffs in Yorkshire, as over 250,000 seabirds flock to the chalk cliffs to find a mate and raise their young. From April to August the cliffs come alive with nest-building adults and young chicks
PA
UK news in pictures 5 June 2022 Performers take part in the Platinum Jubilee Pageant
Reuters
UK news in pictures 4 June 2022 Past and present jockeys who have ridden Queen Elizabeth II’s horses line up dressed in her colours on Derby Day
Reuters
UK news in pictures 3 June 2022 Prince Harry makes a face as he waits for the start of the National Service of Thanksgiving for The Queen’s reign at Saint Paul’s Cathedral
AFP/ Getty
UK news in pictures 2 June 2022 Britain’s Queen Elizabeth II stands on the Balcony of Buckingham Palace bas the troops march past during the Queen’s Birthday Parade, the Trooping the Colour
AFP/Getty
UK news in pictures 1 June 2022 Gardeners David Kay and Lou Singfield tend to the wildflower meadow which has burst into flower at King's College in Cambridge
PA
UK news in pictures 31 May 2022 Sir Sean Connery's Aston Martin DB5 which is expected to fetch up to ￡1.4 million at auction. The family of the James Bond actor, who died in October 2020 aged 90, is selling the 1964 classic car to raise money for a philanthropy fund set up in his name
PA
UK news in pictures 30 May 2022 Corgi Charles and friends enjoy a spot of tea during The Jubilee Tea Pawty at award winning doggy day care, Bruce’s
Ben Stevens/PinPep
UK news in pictures 29 May 2022 Nottingham Forest’s Cafu celebrates after winning the Championship Play-Off Final against Huddersfield Town at Wembley
Action Images via Reuters
UK news in pictures 28 May 2022 Balloons light up as they are tethered to the ground during the night glow at the Isle of Wight Balloon Festival at Robin Hill Country Park, Isle of Wight
PA
UK news in pictures 27 May 2022 A crow chases an urban fox, who has dug up a bird carcass, outside the Old Bailey, central London
PA
UK news in pictures 26 May 2022 Pedestrians walk past a 'Living Wall' art project, produced in collaboration with The National Portrait Galler and the Earls Court Development Company, in west London
AFP/Getty
UK news in pictures 25 May 2022 Guests during a Royal Garden Party at Buckingham Palace in London
PA
UK news in pictures 24 May 2022 People walk past the Liverpool Street station sign along the Elizabeth Line on its first day of service as it joins the London Underground network in London, Britain
EPA
UK news in pictures 23 May 2022 A young child amongst group of people thought to be migrants is carried by a member of the military as they are brought in to Dover, Kent
PA
UK news in pictures 22 May 2022 Fernandinho of Manchester City lifts the Premier League trophy after their side finished the season as Premier League champions during the Premier League match between Manchester City and Aston Villa
Getty Images
UK news in pictures 21 May 2022 France's Thibault Laly during day one of the Mercedes-Benz UCI MTB World Cup event in Fort William
PA
UK news in pictures 20 May 2022 Chef Jamie Oliver takes part in the ‘What an Eton Mess’ demonstration outside Downing Street, calling for Prime Minister Boris Johnson to reconsider his U-turn on the Government’s anti-obesity strategy
PA
UK news in pictures 19 May 2022 Sculpture conservator Marisa Prandelli adjusts a display of heads of ‘Cybermen’ in the monster vault at the ‘Doctor Who: Worlds of Wonder’ exhibition which opens at the World Museum later this month in Liverpool
Reuters
UK news in pictures 18 May 2022 People cross Regent Street, decorated with flags to mark the upcoming platinum jubilee , to mark the 70-year reign of Queen Elizabeth II
AP
UK news in pictures 17 May 2022 Prime Minister Boris Johnson with Transport Secretary Grant Shapps and Mayor of London Sadiq Khan on a Elizabeth Line train at Paddington station in London
PA
UK news in pictures 16 May 2022 Protesters from Border Communities Against Brexit outside Hillsborough Castle during a visit by Prime Minister Boris Johnson to Northern Ireland for talks with Stormont parties
PA
UK news in pictures 15 May 2022 Queen Elizabeth II departs following the A Gallop Through History Platinum Jubilee celebration at the Royal Windsor Horse Show at Windsor Castle
PA
UK news in pictures 14 May 2022 Heat haze softens the scene as a paraglider takes to the sky over the cliffs above Boscombe beach in Dorset
PA
UK news in pictures 13 May 2022 Nazanin Zaghari-Ratcliffe with her husband Richard and daughter Gabriella as they leave 10 Downing Street, after a meeting with Prime Minister Boris Johnson
PA
UK news in pictures 12 May 2022 Rebekah Vardy leaves the Royal Courts Of Justice, London, during high-profile libel battle between Rebekah Vardy and Coleen Rooney
PA
UK news in pictures 11 May 2022 A Goldeneye swims in the rain at Slimbridge wetlands, Gloucestershire
PA
UK news in pictures 10 May 2022 Britain's Prince Charles, Prince of Wales appears on a screen next to a painting of Queen Elizabeth at the Royal Gallery as he delivers the Queen's Speech during the State Opening of Parliament at the Houses of Parliament, in London
AFP/Getty
UK news in pictures 9 May 2022 Linda Bainbridge (left) and Miyuki Griffin putting the finishing touches to The Crown, Orb and Sceptre exhibit as part of A Festival of Flowers' at Salisbury Cathedral. Hundreds of flower arrangers will be mounting 127 individual exhibits throughout the cathedral in honour of the Queen's Platinum Jubilee
PA
UK news in pictures 8 May 2022 Durham Cathedral which stands on The Bailey, a peninsula formed by the River Wear looping around the historic centre of Durham
PA
UK news in pictures 7 May 2022 Girls from Grace and Poise, the world’s first Muslim ballet school, perform during the Eid in the Square festival in Trafalgar Square, London
PA
UK news in pictures 6 May 2022 Ballots are emptied from a ballot box to be counted, during local elections, at Wandsworth Town Hall, London
Reuters
UK news in pictures 5 May 2022 British Prime Minister Boris Johnson arrives at a polling station with his dog Dilyn to vote during local elections in Westminster, London
EPA
UK news in pictures 4 May 2022 Rob Munday, creator of the first officially commissioned 3D/holographic portrait of Queen Elizabeth II in 2004, unveils a previously unseen portrait of the monarch to celebrate the Platinum Jubilee, in London. The new portrait is named ‘Platinum Queen: Felicity’ and is dedicated to the 20 years of friendship between The Queen and her personal assistant and close friend Miss Angela Kelly
AP
UK news in pictures 3 May 2022 Alex Kelly from Eden Architectural Conservation cleans a gargoyle on the north doorway at Rosslyn Chapel in Roslin, Midlothian, as part of conservation maintenance
PA
UK news in pictures 2 May 2022 People enjoy theme park rides at a funfair at Small Heath Park in Birmingham, as the holy month of Ramadan comes to an end and Muslims celebrate Eid al-Fitr
PA
UK news in pictures 1 May 2022 England’s Ronnie O’Sullivan in action against England’s Judd Trump during day sixteen of the Betfred World Snooker Championship at The Crucible, Sheffield
PA
UK news in pictures 30 April 2022 Visitors record images amongst azalea and rhododendron blossom in Richmond Park, London
Reuters
UK news in pictures 29 April 2022 A giant puppet, controlled by four people, called Gnomus, the Caretaker of the Earth, performs at Stonehenge, near Amesbury, Wiltshire
PA
UK news in pictures 28 April 2022 The Prince of Wales and the Duchess of Cornwall in a TV studio during a visit to the BBC World Service at BBC Broadcasting House, London, to mark it's 90th year and to thank staff and learn how they are continuing their operations across Ukraine, Russia and Afghanistan
PA
UK news in pictures 27 April 2022 Trafalgar Square in central London is covered in plants and flowers at the launch of an initiative to rewild and protect 2 million hectares of land. The temporary installation, which is made up of over 6000 plants, flowers, and trees, aims to raise awareness of the importance of biodiversity in urban spaces, with visitors to the site invited to pick up and rehome one of the plants
PA
UK news in pictures 26 April 2022 One of the Liverbirds that sits atop of the Royal Liver Building in Liverpool, is illuminated just before the sun rises over the city
PA
UK news in pictures 25 April 2022 Prime Minister Boris Johnson paints over the white line of the centre circle during a visit to Bury FC at their Gigg Lane ground in Bury, Greater Manchester
Getty
UK news in pictures 24 April 2022 A lone Grenadier Guard during the Dawn Service commemorating Anzac Day at the New Zealand Memorial at Hyde Park Corner, London
PA
UK news in pictures 23 April 2022 Killy Cavendish during St George's Day celebrations in London's Trafalgar Square
PA
UK news in pictures 22 April 2022 A demonstrator holds a pink smoke flare billowing over members of Extinction Rebellion staging a protest against the use of and investment in fossil fuel, outside offices of Vanguard Asset Management on Earth Day in the City of London
Reuters
UK news in pictures 21 April 2022 The Honourable Artillery Company (HAC), the City of London's Reserve Army Regiment, fire a 62 Gun Royal Salute at the Tower of London to mark the 96th birthday of Queen Elizabeth II
PA
He added: "They will also know that the Parliamentary authorities must be taking steps to block such access. Revealing the number of attempts to view explicit material each year tells us something significant about Parliament but little about its internet security vulnerabilities, particularly as the number of failures to block access and the sites which have not been effectively blocked have not been requested."
A spokesperson for the Commons authorities said: “The House of Commons did previously release information on web access requests.
"However, after reassessing cyber-risk in 2017, it was determined that it presented a security risk and exposed the parliamentary network to an unacceptable amount of risk, and future requests were subsequently exempted under grounds of national security (s.24 FOIA) and law enforcement (s.31 FOIA).
Recommended Inside Politics: A Frosty intervention Boris Johnson warned he has until the autumn to save his premiership Lord Frost warns PM has until autumn to save himself from being ousted - follow live
Mr Parish said he originally accessed pornography by accident while searching for information about tractors, but that on a second occasion he had done so deliberately.
On another occasion in 2017 another Tory MP, Damian Green was sacked as first secretary of state after admitting he had lied about the presence of pornographic images on his House of Commons computer. He maintained that he did not “download or view” the pornography, but accepted that that he “should have been clear in my press statements” about the presence of the images on his computer.