“I decided I was going to be an MP when I was 13,” Andrea Leadsom reveals.

It was the mid-1970s. Industrial strife, blackouts and a weak economy had earned Britain the unwanted label of “the sick man of Europe”.

Her political conversion came less from Britain’s post-War decline than the Cold War and what she describes as her feeling of “absolute terror” at the threat of a nuclear conflict.

“I thought, if I go and become and MP I can save the world from a nuclear holocaust,” she says.

Forty years later, Mrs Leadsom finds herself at the heart of a government confronting a new kind of terror: the threat from jihadists who have attacked Europe 14 times in the past 14 months.