Nearly 300,000 "attempts to access websites categorised as pornography" were made from computers within the British Parliament in the last year, official records show.
The figure - which represents more than 800 per day - was released by Palace of Westminster IT chiefs in response to a freedom of information request.
It covers devices linked to the Parliamentary Network, including those used by MPs and peers, their staff and other employees.
Officials sought to play down the significance of the total, insisting it was inflated by pop-ups, auto-refresh and other web design features and did not reflect deliberate efforts to access sexual content.
They are also investigating the reason for wide variations between the monthly figures - with as many as 114,844 in November but just 15 in February.
