In the white heat of the debate on whether or not there should be a TV debate on Brexit between Theresa May and Jeremy Corbyn, you could be forgiven for not noticing the TV debate on Brexit between Theresa May and Jeremy Corbyn that happened on Wednesday lunchtime, as it does at random roughly once a month, replacing the scheduled programming known as “Your NHS in Wales is worse than my NHS in England”.

If Theresa May and Jeremy Corbyn approached Prime Minister’s Questions as a showcase through which to convince the general public to spend next Sunday night listening to them argue about future customs arrangements instead of watching Harry Redknapp eating an ostrich penis then it was, at best, a partial success.

When, for example, Jeremy Corbyn told the prime minister that, having claimed her deal is the “best possible deal available AND the ONLY deal available, so by definition it must also be the worst possible deal”, he will have to hope the viewing public realise this kind of searing analysis, traditionally the reserve of the junior school playground, must be because he is keeping his real zingers hot for prime time.

Which is not to say Theresa May’s position is not, well, hopeless. This morning, the chancellor was on the radio, briefing the economic forecasts, all of which have concluded that Theresa May’s deal will leave the country worse off than staying in the EU, but the other options are worse.

But a matter of hours later, we learned from the prime minister that, actually, this analysis “does not show that we will be poorer in the future than we are today”.

And that, in a sense, is true. If you or I were to chuck 10 grand down a well today, one would hope that by, say 2030, we might have more than 10 grand in the bank again, and so we would not be poorer in the future than we are today. And by this logic, Theresa May is defending her decision to follow the “will of the people” and take the public finances direct to the nearest well.

Of course, the prime minister hopes the TV debate will allow her to show Labour’s Brexit position for the sham that it is, and her dry run at that was that Labour’s fabled “six tests” for any Brexit deal. “All they have is a series of six bullet points,” she said. “My weekend shopping list is longer than that.”

Which will have come as something of a shock to No 10 staff, whose timetable for selling the Brexit deal has now been leaked. Wednesday was “the economy”. By Saturday and Sunday, Theresa May is meant to be on to “digital” and “the Brexit deal”. If she is, in fact, off to the shops, someone should have told her that Black Friday was last week. There were some great deals to be had on 99 new backbenchers prepared to support her deal, not to mention a new Brexit deal with the EU that stands even a vague chance of making it through the House of Commons.

She’s going to have to find one that costs a lot less than £39bn, takes us out of the single market and the customs union while replicating the “exact same benefits” of both, keeps us aligned to EU customs regulations while simultaneously allowing us to strike our own free trade deals. Oh, and not have any kind of backstop over the border in Ireland, to mitigate against the risk of the “technological solutions” for the Irish border that don’t currently exist not being invented in time.