You could say it was all a bit previous. With Theresa May’s inner cabinet off to Chequers in the afternoon to see if it could agree – if only for a day or so – on a vaguely plausible Brexit negotiating strategy, it was expecting a lot of the junior Brexit minister Robin Walker and Tim Barrow, the UK’s ambassador to the EU, to provide any great clarity on the government’s position before the European scrutiny select committee in the morning.

There again, even on the off-chance that the prime minister were to come up with some sort of Brexit Santa list later in the day it would be highly unlikely that anyone would bother to tell Walker. Or, if they did, that he would understand. So there was as much to be gained from grilling him before as after.

Brexit transition extension could cost Britain £5bn, MPs say Read more

Walker is what’s known in government as “a useful idiot”. A little-known but much-valued asset in Westminster. Someone whose sole function is to know almost nothing about anything and therefore can be relied on to hide the government’s incompetence behind his own uselessness. Whenever the Brexit department is in trouble, it’s Walker – or his sidekick, Steve Baker, another useful idiot – who gets sent out to defend the indefensible in parliament. Either to claim the economic impact assessments that David Davis had said existed in excruciating detail didn’t really exist at all, or to argue that the impact assessments that did turn out to exist didn’t exist after all.

In any case, the European scrutiny committee were determined to get their money’s worth. With most of the Labour remainers unaccountably absent, the committee closely resembled the inner circle of the European Research Group. As well as the chair, Bill Cash, there were David Jones, Marcus Fysh and Andrew Lewer – all paid-up members of the 62-strong group of Tory MPs whose sole purpose in life is to declare war on the EU and to make the prime minister’s job almost impossible. To which you could also add Labour’s Kate Hoey. It’s only a matter of time before the ERG welcome her as an honorary member.

It was the ERG members who dominated the session. They scent betrayal at every turn and had sent a warning letter to the prime minister earlier in the week threatening her with seven plagues and the loss of her job if she didn’t deliver on the will of the 62. Cash got things under way. If the transition period went on beyond December 2020 was it possible that Britain could end up paying more than the £39bn it had already promised?

The useful idiot made the fatal mistake of trying to appear as if he knew what he was doing and predictably ran headlong into trouble. The government was very confident that a deal could be reached within that period, but if it couldn’t then, yes, we would probably have to divvy out a bit more. To any normal person this merely seemed a statement of the obvious. Not to Cash, who reddened with fury. In his world that could mean we would end up giving money to the EU indefinitely. “Servitude,” he muttered indignantly. “Vassal state.”

Barrow tried to come to the rescue. He has the career diplomat’s knack of talking in aural valium, wittering on at length about not very much in a manner that makes you think you understand what he’s saying until you realise you can’t even remember what he said in the previous sentence. Still, 10 minutes of Barrow was enough to get the useful idiot back on track, and he was soon back to mouthing sweet nothings himself.

He was sure everything was going to be fine because he had read a memo saying everything was going to be fine. Northern Ireland would miraculously sort itself out, and he was sure that we would be able to do free trade deals during the transition period apart from the ones we wouldn’t be able to do because we were engaging proactively going forward.

The clock moved round to midday and the hearing came to an end. Still, it hadn’t been a total waste of time. The useful idiot had done his job by being a useful idiot. And the ERG had got a free session of anger management therapy.