Iain Dale is Presenter of LBC Drive, Managing Director of Biteback Publishing, a columnist and broadcaster and a former Conservative Parliamentary candidate.

It was around 10am on a Saturday in December 2012. I was in bed. The previous night I had given a speech to David Cameron’s Conservative Association in Chipping Norton. The bastards had heckled me over my views on gay marriage. I thought I deserved a lie-in.

Suddenly my phone rang. I sat bolt upright in bed. “I have the Prime Minister for you,” said the voice at the other end. And there was I, stark bollock naked in bed.

“I hear you had some fun last night with my lot,” laughed the Prime Minister. I retorted: “Clearly your modernising agenda hasn’t worked on them.” After he’d thanked me for doing the speech he suddenly asked me how I thought things were going. I’ve no clue what I said, but I do remember commenting that I thought the Number Ten media operation needed a bit of sharpening. At that, the Prime Minister launched into a staunch defence of Craig Oliver. It turned into a bit of a rant. “I don’t know why people keep having a go at Craig. He’s bloody brilliant.” I hadn’t actually mentioned Oliver, although I do remember saying that I thought he was too concerned with keeping BBC news programmes happy and didn’t seem to get that there were actually other broadcasters who mattered too.

I tell that anecdote to underline the fact that Oliver and Cameron were as close as close could be. And they remained so until the bitter end. Oliver would have died in a ditch for Cameron, and Cameron wholly trusted his judgement and strategic thinking. When you get to the end of this book you are left wondering whether the former Prime Minister was right to.

Unleashing Demons is based on the daily diaries Oliver kept from late 2015 until June 23 2016. Given how often he complains about not having any time to do anything, you wonder how he had the time to keep a record, but we should all be very grateful that he did.

This is contemporary history at its best, and it is probably the best account of the Remain campaign we’re likely to get. Yes, it’s instant. Yes, it’s partisan, but he was there – there in all the important meetings. Yes, it does sometimes have the faint echo of a slight rewriting of events to make the best of them. Yes, some of the analysis smacks of being wise after the event, but make no mistake, anyone thinking they should give this book a miss is missing out.

It’s full of juicy anecdotes and riddled with emotion. At times the reader wonders whether Oliver was on the verge of a minor breakdown. By the end of the campaign he was pretty sure his health had been affected. Those of us who have been through a general election campaign know the pressures that come with it, but that generally only lasts for a few weeks. This campaign was full on for six months.

If you hate Michael Gove, you’ll love this book. If you think Theresa May is a bit of a calculating minx, you’ll have your suspicions confirmed. If you think everyone on the Leave side of the debate was an out and out liar, you’ll love it in spades. And if you think the Remain side was full of decent people who were the true patriots, again, this will be right up your street.

According to Oliver, the motives of the Leave campaign were universally dodgy, malign and ignorant. Their tactics were disgusting and it was all the fault of Dominic Cummings. Somewhat bizarrely, the director of Vote Leave, Matthew Elliott, only rates two mentions. Project Fear wasn’t something ‘Stronger In’ indulged in, no Siree. All down to Vote Leave, you see.

If you’re running a campaign you have to be a true believer. You have to believe in your product. But the fact Oliver was even running the Stronger In campaign – and this book makes clear he was – came as a bit of a revelation to me. I had always thought it was Will Straw. Even Straw plays only a peripheral role in this book. OK, he rates rather more mentions than Elliott, but he only appears when he’s agreeing with Craig, or saying something wholly uninteresting. If you believe Oliver, he was setting the strategy and the Prime Minister was signing it off. And this was one of the reasons why the campaign never really sparked. Will Straw is a nice guy, but hardly an inspirational figure. Oliver is a bit more worldly-wise, but he’s from the media. He’s not a political strategist and has never fought an election campaign. What Stronger In needed was a Lynton Crosby figure. The only figures remotely involved who could have fulfilled that role were Peter Mandelson and/or Alastair Campbell. But they had too much baggage to play more than a peripheral role.

This book is too instant for Oliver to really understand the mistakes that were made. Not all of them were made in the campaign. The seeds for the Leave victory were sown many, many years ago. Most recently, the failure of the Blair government to restrict Eastern European immigration in the early 2000s set alight the flames of the immigration debate. Stronger In failed to engage on the subject, mainly because they didn’t have an answer to it. They bet the house on the economy, and it blew up in their faces. They couldn’t have predicted that Labour would fail to mobilise their voters and seem totally disinterested in the fact that a good many of them had already made the trip to UKIP-land.

The BBC plays a big role in this book. Having come to Number Ten from being editor of the BBC Ten O’Clock News, Oliver comes across as very naïve about the way the BBC operates. He genuinely believed the BBC was biased against Stronger In and there are dozens to examples of angry phone-calls to various BBC executives complaining about their coverage. Some of them were legitimate, but his inability to understand that the Leave campaign felt the same and were doing exactly the same thing is rather odd.

I wanted to publish this book, and met Oliver to discuss doing just that. In the end he went with a big publisher, Hodder, and I have to say they’ve done a terrific job in bringing the book out so quickly. Normally, when a book is published in double quick time, it is riddled with errors. I spotted only two – a missing ‘a’ and Robert Syms MP’s name spelled incorrectly.

This book is meant to be a diary, but it’s actually a book based on a diary. It’s a strange way of writing a book, but it works. Alastair Campbell’s diaries are raw and from the day itself. I’d love to read Oliver’s raw diaries. I wonder if by the end of them, I’d have a different understanding of events than the one offered in this book. I hope not, but there’s always the doubt that inconvenient facts and opinions might have been excised from a book like this. In a way it’s inevitable. There are no great prime ministerial temper losses revealed here, but I can’t believe it didn’t happen once. There are no shouting matches at ‘Stronger In’ board meeting. Yeah, right…

Overall, though, this book rivals Ed Balls’ Speaking Out as the most enjoyable political book I have read this year. It has pace, insider info and a bit of chutzpah. As I finished it, I wondered if Cameron has read it yet. It may be better for him to leave it for a few months… It would be like picking at a scab.

Unleashing Demons by Craig Oliver is published by Hodder in hardback at £20.