Donald Macintyre's Sketch: No Douglas Carswell – but Ukip’s presence in the Commons is still felt

Expected, as Ukip’s first ever elected MP, to inject an electric new current of excitement through the Commons, Douglas Carswell has been a crashing disappointment. Today, for PMQs, he didn’t even show up.

Why? Was it because the left-wing Labour MPs among whom he has bizarrely chosen to sit packed their bench to squeeze him out? Was it the horrific prospect of being on the same side as Harriet Harman while she flaunted what Carswell would regard as an unacceptably PC “This is what a feminist looks like” shirt (to taunt the PM for refusing to don such a garment for Elle magazine)?

Or had he succumbed to tarsal tunnel syndrome, the absent politician’s malady now made fashionable by North Korea’s President Kim Jong-un? No, he tweeted to his fans, he was on by-election duty in Rochester, “the seat that really matters”. (Which is a bit rough on his own Clacton constituency)

But he may also have had an – entirely correct – intuition that Ukip would dominate the proceedings whether he was there or not. The unedifying Miliband-Cameron exchanges on immigration consisted – in effect – of “Are you going to apologise for saying you would bring immigration down to tens of thousands and it’s now 243,000?” “No, you should apologise for the shambles Labour made after letting all those East Europeans in.” “No, you say sorry.” Etc etc.

Even Carswell, you felt, might have paid lip service to the idea that some immigrants did good, even essential, jobs.

Miliband did mention – albeit in passing – the Government’s “callous” decision not to rescue drowning would-be migrants. And he did mount a somewhat less Ukip-tinged challenge by accusing Cameron of delaying a vote on the European Arrest Warrant till after the by-election. Then Cameron surprised everyone by saying he was going to have the vote before it, adding gleefully. “His questions have just collapsed.” At which point Cameron all but cocked a snook at Miliband and shouted “Yah boo sucks”. Consoling himself, perhaps, for probably losing Rochester to Ukip.