David Cameron has announced this afternoon that he is to quit the Commons – not at the next election, but forthwith, triggering a by-election.

Perhaps the best response (and certainly the most consistent) is to reproduce what we wrote in March earlier this year, after he had said that it was “very much my intention” to stand for election in 2020.

“A contributor to the low standing of politicians is a sense that they enter the Commons to grab high office, use it to polish their CVs, and then push off to line their pockets. Tony Blair walked out of Parliament on the day he departed Downing Street and has not gone back – that’s to say, to the Lords, membership of which would require him to disclose his interests. Gordon Brown hasn’t gone to the upper house either and nor, we have to add, has John Major.

A suspicion that David Cameron and George Osborne might abandon the battlefield to make their millions, leaving the poor bloody infantry on IPSA-overseen expenses and with curtailed outside interests, hasn’t helped their joint leadership of government since 2010. (Yes, yes: I know that MPs are very well paid and in the top three per cent of so of earners. I’m just telling you how some of them feel.)

The Prime Minister’s words yesterday were not exactly clear-cut – saying that it is “very much [my] intention” to stay on in the Commons is not definitive, and he was, after all, speaking to Radio Oxford: some of his Witney constituents will have been listening in. But what he said was a signal in the right direction. For the faster turnover is in the Commons, the more continuity rises in value.

It needs former Ministers who can say, as governments rush their plans out: “hang on a moment: we tried that, and it didn’t work”. Or, even better: “we tried that and it didn’t work – but here’s how it might have done, and how this idea could do, if adapted”. Endurance isn’t everything, but it counts for something. So let’s give Cameron a cheer this morning (while prudently saving the other two up for an announcement, if it comes).

As Iain Dale suggests on this site today, his presence would be a real plus for the post-2020 Parliament. ConservativeHome hasn’t always agreed with him (to put it mildly), but he has headed a government that has carried out more public service reform in a single term than Margaret Thatcher managed until her third: indeed, the Coalition arguably saw through even more. He deserves great credit for that and for much else too.

Oscar Wilde wrote that experience “is the name that men give to their mistakes”: maybe so. But whether this is true or not, the Prime Minister should stay on to share his. As a not-so-much-elder statesman, he could give it the benefit of his finest hours, worst moments, close shaves, cock-ups, might-have-beens and, yes, wisdom. He could share what he has learned. He is very much part of the furniture, and should grace the Chamber for many years yet.