Picking your favourite book of all time is an almost impossible task. How can you compare Watership Down with Animal Farm with  or, dare I say it, The Rats by James Herbert? How do any of these compare to some of my favourite political tomes like Gyles Brandreth’s Diaries, Breaking The Code, or Denis Healey’s memoirs, aptly named The Time Of My Life?

Because I am a publisher by day (and a radio presenter in the evening) I get little time to read for pleasure, as I am invariably reading author manuscripts – not that they are always devoid of pleasure you understand. When I do get time to read for pleasure I tend to concentrate on political (auto)biography or books by footballers. My favourite literary genre is political diaries. I’ve read them all – Alan Clark, Barbara Castle, Tony Benn, Richard Crossman, Gyles Brandreth and many other lesser known figures.

But my absolute favourites are the five volumes of Alastair Campbell’s diaries, the most recent of which Outside, Inside my company (Biteback) was proud to publish.

I’ve read every word of all five volumes and no one who professes to understand the Blair years can possibly do so without doing the same.

I’ll be honest, I’m a massive Alastair Campbell fan. Always have been, even before I met him or read a single word of the diaries. In some ways he’s a bit of a hero of mine. We’re very different in all sorts of ways, but similar in others. We’re both obsessed by politics and football, we both have addictive personalities, we’re both difficult to live with. We both tend to overshare and bare our souls in public, much to the irritation of those close to us. But this is why the Campbell diaries are so addictive.

Alastair Campbell has done more than most to raise the profile of mental health in Britain, and his diaries have played a big part in this. The passages on his struggles with depression can be tear-inducing. His emotional intelligence shines through, yet in volume 5 we learn that Tony Blair had no idea his Director of Communications was a manic depressive until he read the manuscript of volume 1.

I am sure there are times when Campbell has self-edited in order to spare certain people’s feelings, but there’s scant evidence for it. He doesn’t hold back, but his loyalty to his friends also shines through. If you’re in a hole, and Alastair Campbell is your friend, you’d be able to rely on him to help dig you out of it. I know. He did it for me once, and it’s something I will never, ever forget.

Someone asked me recently who I would like to be if I wasn’t me. I replied that I was quite happy being me, but if I weren’t me, Alastair Campbell would be right up there as someone whose life I’d quite like to have led. Well, possibly without the black dog periods… So many people misjudge Alastair Campbell because it’s the trendy thing to do to hate him. Look beneath the press cuttings and you’ll find a kind, decent, loyal, talented, strategically brilliant, family oriented individual who is possibly one of the most misunderstood people in British public life.

Alastair Campbell’s latest volume of diaries, volume 5, Outside, Inside 2003-2005 are out now, published by Biteback at £25. His next volume, 6, Transfer Of Power 2005-7 will be published in September.

Iain Dale presents the Drivetime show on LBC Radio. He is also managing director of Britain’s leading political publisher, Biteback Publishing. His latest book is The NHS: Things That Need To Be Said, published by Elliot & Thompson, £8.99.