Norman Lamb is one of Britain’s most tireless mental health campaigners, an MP who doesn’t just pay lip service to this most important of subjects - unlike so many other politicians.

I meet the Liberal Democrat MP for North Norfolk in his office in Portcullis House, where he has dashed from a meeting in Bedfordshire with CHUMS, a charity that offers care for young children with mental health difficulties. Lamb may no longer be a health minister, but he remains a passionate crusader on behalf of the mentally ill – he was pleased that David Cameron made a speech on the subject in February, but as Lamb says, “there is a massive gap between the rhetoric and the reality.” Promises broken. Commitments cast aside.

This angers Lamb because he knows all too well the devastating impact of mental illness. When he talks about how neglected it is in the health service, how this neglect impacts upon our national productivity in terms of sickness absence, benefits bills and lost tax revenues, this isn’t just him wheeling out dreary Whitehall wonkery. It’s him talking from the heart.