You know the government is in trouble when Chris Grayling feels able to offer it advice on how it could handle things better. Chris Grayling, commissioner of ferries that don’t exist. Chris Grayling, subject of uncounted “Top Ten Chris Grayling Disasters” articles. There are journalists whose phones suggest “Grayling” every time they type “failing”. Chris Grayling, who couldn’t win a rigged election to chair a parliamentary committee.

So, anyway. Boris Johnson came to Parliament on Tuesday to persuade MPs to vote for his new Tier system. There was no danger of losing the vote – opposition parties were abstaining – but he was in trouble with his own side. Conservatives are angry to discover that the month-long lockdown is ending with the country only very slightly less locked down.

The prime minister insisted this wasn’t the case. From Wednesday, he said, everyone would be “free to leave their home for any reason”. What was more, “when they do, they’ll find the shops open.” Perhaps, at some level, Johnson knows that “the government will now permit you to leave your home – for any reason” is not the Advent message he imagined he’d be delivering a year ago.

Desperate to get his MPs back on side, the prime minister began spraying promises around, though not all of them were as impressive as he seemed to think. Were MPs worried that pubs would collapse? Why, the government would give them £1,000 each! For context, that’s about a fifth of what Johnson got paid for each of his weekly columns in the Telegraph. No one knows if he ever bought a round.

As Tories rose to point out that their low-infection constituencies had been put into Tier 3 lockdown because they were in the same county as distant highly infected areas, Johnson was swift to promise change: “As we go forward, the government will look at how we can reflect as closely as possible the reality of what is happening on the ground to local people.”

So even before the vote, there was the promise of a new system to replace tomorrow’s system, which is replacing Lockdown Two, which replaced the previous month’s Tiers And Definitely No Lockdown, which replaced the Rule Of Six, which replaced Whack-A-Mole, which replaced Lockdown One, which replaced Shaking Hands With Everyone I Meet.

Labour’s Tanmanjeet Singh Desai wanted to know why the wider regional approach hadn’t been applied in his constituency of Slough, which has been carved out from the rest of Berkshire. Any readers who know why Her Majesty’s Government might want to avoid putting the area around Slough into Tier 3 should send answers on a sterilised postcard to Windsor Castle.

Edward Leigh wanted Johnson to promise that he and Matt Hancock would “do their level best” to get Lincolnshire out of Tier 3 by Christmas. It was a ridiculous request for something simply beyond the prime minister’s control. The tiers are set on the basis of a careful scientific assessment of the way that the disease is spreading, which is the result of local conditions and behaviour. Johnson could no more promise that than… oh, what’s that you say, prime minister? “Indeed! I can certainly give that assurance.”

No one, surely, expects a prime minister to actually remember or stick to the things he might have said

Perhaps even Tory MPs, though, are starting to sense that a Boris Johnson promise isn’t worth very much. The best way to understand the prime minister’s words on these occasions is to picture him as a man pulling on his trousers in the bedroom of a woman whose name he has already forgotten. It’s a stretch, I know, but work with me. In those circumstances, as a chap tries to remember what happened to his cufflinks, he’s apt to say, more or less, whatever is necessary to get safely out of the front door and into a cab home, possibly picking up some flowers for the wife on the way. No one, surely, expects a prime minister to actually remember or stick to the things he might have said.

Keir Starmer made this point, though sadly not in those terms. “The prime minister has a record of overpromising and underdelivering – short-term decisions that then bump into the harsh reality of the virus,” he said. “After eight months, the prime minister should not be surprised that we and many of the British people are far less convinced this time around.”

Johnson said it was “extraordinary” that Labour was abstaining, rather than supporting the system he had just admitted needed reform. This is a man who organised a trip to Afghanistan to get around a pledge to vote against Heathrow expansion, so there’s always something brilliant about him accusing other people of political opportunism. You expect him to follow it up with a horrified anecdote about a romance which finishes “and they’re not even married!”

He followed it up by telling Labour’s Toby Perkins to “think very carefully about what he’s just said.” Boris Johnson telling other people to think very carefully about what they’ve just said. Boris Johnson. It couldn’t have been weirder if he’d advised the chamber to always use a condom, “and, answer every unknown number that calls you! You never know.”

Damian Green, upset about Kent’s restrictions, also had his doubts about the Christmas relaxation of the rules. If it went wrong, the ex-deputy PM said, “we’ll have exchanged a weekend of fun for a long winter of regret”. Or to put it another way, the prime minister is now delivering to the entire country an experience he used to deliver one woman at a time.

Chris Grayling, though.