Ironic, then, that it is one of the few governmental functions to ban workers from using mobile phones. On entering the building, everyone has their phone confiscated by the receptionist, who is protected by thick glass.
The ban is designed to stop any duplicitous staff or visitors recording conversations, lest the information falls into the wrong hands, an insider tells us.
An official statement emailed to Diary explains: 'Departments never discuss security measures.' Quite right: you never know when an al-Qaeda operative will be round the corner armed with a Motorola Pebl.