David Cameron must resign after finally admitting that he did have a stake in his father's offshore fund

David Cameron is a man with a reputation seemingly made of titanium. Really, who does this guy have to piss off to merit serious calls for his resignation? Considering it’s just been revealed that he did actually have a stake in his father’s offshore investment fund, the lack of outrage is astonishing.

Read more of our Panama Papers coverage

He annoyed steel workers, migrants, those on benefits, students, the disabled, the working class, the unions and women ages ago. But it's OK – those people don’t matter in the grand scheme of things.

Then he came for the middle classes, which was a bit of a shocker. The Prime Minister has presided over four junior doctors’ strikes; forced teachers into debating industrial action over plans to turn schools into academies; and angered solicitors over cuts to legal aid.

Of course, he also upset the whole nation’s moral sentiments with the small issue of PigGate. This pales in comparison, though, to the moral disgust I feel over the fact that he’s been neglecting to tell us about that secret stake in Ian Cameron’s offshore tax avoidance scheme all week. Now it seems pretty clear why his response to the Panama Papers lacked a decisive call to action – or indeed a straight answer to almost anything until now.

I say it again as it bears repeating: what does a man have to do around here for one single call for resignation? Jeez.

But still, maybe I am tainted by my own lefty sentiments. Let me step into some aspirational voting loafers, or whatever footwear you guys wear. Let’s remember for a second the Icelandic Prime Minister, Sigmundur Davíð Gunnlaugsson, whose ties to an off-shore company with multimillion-pound claims on Iceland’s three collapsed banks - which almost brought the country to its knees in 2008 - were revealed in the Panama Papers. How do they compare to Cameron’s little revelation?

It turns out they’re not so different. But what’s most stinging is the sheer hypocrisy of Cameron. After all, this is the man who made great efforts to increase funding for HMRC tax inspectors; abolished permanent non-­dom status from April 2017 and proposed an international anti-corruption drive in the light of the Fifa scandal.

But it seems like Cameron isn’t going to do a Gunnlaugsson anytime soon. The only other option is a motion of no confidence.

Perhaps this is time for Corbyn to step up to the plate – or indeed Cameron’s own party. If there were ever a time for the in-fighting Tory backbenchers to stab their leader in the back, this is it.