“Power doesn’t always corrupt. What power always does is reveal. When a guy gets into a position where he doesn’t have to worry any more, then you see what he wanted to do all along.”
— Robert Caro

John Bercow’s autobiography has been described by reviewers either as a study of rudeness and score-settling, or as an insight into whether he was, or was not, a bully. But like all political autobiographies, Unspeakable is an attempt to recast recent history in the hope that the author can decide how he will be remembered. In Bercow’s case, he dedicates his book to “all who believe that Parliament’s duty is not to bend the knee to the government but to exercise scrutiny of it.” He says that this was his “overriding mission as Speaker”.

I’m not so sure.

For anyone who had anything to do with Bercow’s Speakership, it is unlikely that they will ever forget it. It was incredible — the most systematic accrual of untrammelled political power which, in the name of advancing the cause of parliamentary democracy, came very close to ending it.

For a couple of years of his Speakership, I was one of his three Deputies. The Deputy Speakers have their own corridor in parliament from which, every morning before parliament sat, we would process. Past the panelled office of the Leader of the House, behind the Speaker’s chair, along the senior clerks’ corridor and into Speaker’s House.

The Serjeant at Arms would be waiting at the front desk of the Speaker’s secretary, and the clerks would join just after our arrival. The Deputies would receive the lists of MPs who would want to be called to speak in the day’s debate and then the whole group, in file and order of seniority, would proceed to the Speaker’s study. At the door we would, again, wait until he was ready to receive us. Who knows how ancient these formalities were.

The assistant to the Speaker’s secretary would enter before us and when all was ready, open the large oak door and stand aside, back to the bookcase, front facing the Thames. With head bowed, he announced us by our titles, as might an equerry. We would move to our allotted chairs and stand, waiting for the Speaker.

What happened next depended on Bercow’s mood. Some days he would be jolly, already at the table, beckoning us to sit, as though to reprimand us for standing on ceremony in such a fusty way.

More frequently, he would hover around his chair looking as though he might sit, and then not sit. We learned not to move until he had committed himself and was actually sitting.

Here was a man practising the exercise of power in a way that no other Speaker before him had ever dreamt of doing.

Speaker’s conference itself was less a meeting and more of an audience. There was never any need to participate other than to hear what Urgent Questions had been chosen and, some mornings, to watch an impression of a Tory MP. It was an extraordinarily courtly ritual for a man who dedicates an entire chapter of his autobiography to being a moderniser.

Many of the changes he introduced were things that I supported — bringing the UK Youth Parliament in for its annual sitting, the opening of a nursery, encouraging applications from BAME candidates in senior roles, for example. But that isn’t the point. The modernisations had the effect of extending the reach of his powers beyond chairing debates in the Chamber and into the tiniest recesses of parliamentary administration.

In some cases, these “modernisations” were less tiny. When Robert Rogers (now Lord Lisvane) retired as the most senior clerk of the House, Bercow took over the appointments process by selecting his own panel and attempting to bring in a woman with no experience either of the UK parliament or of being a clerk. Bercow will not have been the first Speaker to have had creative tensions with senior clerks. It is their role to advise and to challenge the Speaker and they can sometimes come across as enjoying their learning a little bit too much.

There’s an apocryphal story about the senior clerks that I long to believe, that they tell each other jokes — in Latin. For a man who has a thing about Oxbridge toffs in the way Bercow does, it will have added to his dislike of them, but to try and displace them was completely new.

He failed, but after that he took less and less notice of the senior clerks, making increasingly important decisions against their advice. And as he did so, he saw quickly that there was no one to challenge him. Occasionally an MP like Andrew Bridgen would stand up and make a hostile point of order, but Bercow was the Speaker. He could choose who got to speak and who did not. There were MPs on the Conservative side who never came into the Chamber when he was in the chair, knowing that they would never be called. He quite literally always had the last word which was very often, “And there’s the end of it.”

Parliament had taken on the powers of the executive. In another country we might have called it a coup

He was masterful in the chamber. He loved difficult sessions and debates. Sitting in the chair when a row is brewing is a terrifying experience because you’re not really sure whether you’ll be able to control it. But he lived for those moments and was never more in his element than in the high-octane Brexit debates and the chaos of prorogation that followed.

The pity was that all this power he gathered to himself was invariably used for one thing — to settle old scores. In that light, everything he did, every modernisation, every quip and nasty comment, was aimed at people he felt had snubbed him during his long political career, or people he felt had not recognised his abilities in the way they ought.

The people he insults in his autobiography are all people he has history with: Michael Howard, Michael Gove, David Cameron, Theresa May, Andrea Leadsom, Andrew Lansley, William Hague, Anna Soubry. I might have missed it but there don’t seem to be many Labour people he insults in the same way.

The pity is that even though he achieved such great office he used his powers to punish those he disliked, and did so in the name of Making Parliament Great Again. Accumulating ever greater powers under the banner of “modernisation” came to a great flowering at the height of the Brexit debates. It was, though, also what brought him down.

A hung parliament, a prime minister who couldn’t pass legislation nor call a general election, a prorogation that was deemed unlawful, all provided Bercow the power vacuum that he needed for his final push. He took upon himself the power to legislate. Against the frantic advice of the clerks he was now ignoring, Bercow made a decision to allow Hilary Benn, an opposition backbencher, to bring forward a bill that would stop a no-deal Brexit.

“The request was legitimate under Standing Order 24 which allowed for emergency debates. I granted the request. Those MPs won the vote, introduced the so-called Benn Bill and parliament passed it so that it became an Act.”

Standing Order 24 does indeed allow for emergency debates. It does not allow for legislation. That is the role of government.

Here, without anyone to stop him, John Bercow transferred the powers of government to parliament. Parliament’s role was no longer to scrutinise and hold to account, it was to legislate. Parliament, with John Bercow at its helm, had taken on the powers of the executive. In another country we might have called it a coup.

It’s impossible to know what would have happened if an election had not been called. A parliament with executive powers but without the ability for anyone to hold it to account might have gone very badly wrong.

As it was, Speaker Bercow retired and was replaced by Speaker Hoyle, a man who has seen what happens when the mighty forces of the chair are unleashed. He has quietly put the genie back in its bottle and firmly placed a cork in it. Everyone in parliament, no matter what side of the Brexit debate they were on, speaks not of the relief of having a majority to get parliament working again but of Lindsay Hoyle being in the chair.

John Bercow is an extremely gifted man. Possessing a near-photographic memory, a hunger for procedure and an endless appetite for politics, he really could have been remembered as one of parliament’s greats.

One day at Speaker’s Conference he managed to get a very unlikely Urgent Question to be answered by a senior Foreign Office minister he particularly disliked. There was an empty can of Diet Coke beside him on the table. “Yes!” He banged his fist so hard on the can that it flattened to a perfect puck. He picked it up and threw it, almost without looking, at least five metres over to the bin. It was a perfect shot.

It’s a shame that a man with so many talents was undone by his appetite for vengeance.