“Crucially, we want to encourage other whistleblowers to come forward,” she said. “It is a very frightening and lonely process to go through. We need to show that they can not only survive the process, but even flourish.”

Machon’s experience in the 1990s in some senses prefigured what sources such as Edward Snowden and Chelsea Manning are going through today.

An intelligence officer with the British MI5 service for six years, she and her partner resigned in 1997 and made public a number of allegations about secret and potentially criminal activities.

Among these, they alleged that intelligence services had been keeping secret files on government ministers, had illegally tapped phones, had failed to stop Irish Republican Army bombs and subsequently lied about their actions, that people known to be innocent had been convicted of bombing crimes, and – most explosively – that MI6 had sought to have Libya’s Muammar Gaddafi assassinated.