Cameron is on probation - his community service order is a clean-up of offshore corruption.
I had a lot of sympathy with the protesters marching on Saturday on Downing Street calling on David Cameron to resign.
But I didn't join them. And that wasn't just because I had an event with Another Europe is Possible, an exciting campaign that's offering a different vision of a social Europe, a people's Europe, at the same time.
One reason was practical - what difference would it make if David Cameron resigned?
We'd have a Prime Minister Osborne, Johnson or May. No real change there then.
And more, the issues raised by the Panama Papers would be seen to be dealt with, at least in Britain, then that would be an excuse to leave the massive systematic problems that they expose to remain.
There's no doubt that this is a story that goes to the heart of the British financial and political systems - more than half the companies in the Panama Papers are based in Britain, and it's clear that systems we are responsible for are allowing corrupt politicians and officials around the world to rob their people on a massive scale. It's our system that's robbing health services of essential funds, taking food out of the mouths of children.
That's not to say that we should allow the pressure off the prime minister.
David Cameron demonstrated through five days of obfuscation that he himself acknowledged he had something to hide about his financial affairs - and he is a man who has been proclaiming his intention to crack down on tax-dodging and offshore havens while failing to act.
So I'm regarding him as a prime minister on probation - his community service order being to take big, effective steps to clean up on the offshore mess.
Next month we have what David Cameron has himself been proclaiming as a critically important global summit on shutting down the tax havens. One that Cameron will now be under immense pressure to make effective.
That should be regarded as a test.
A further argument against immediate resignation is the political context.
We have in less than a month important elections on these islands - elections to the Scottish Parliament, the Welsh Assembly and many local authorities around the nation. These deserve proper attention and focus, not the distraction of a prime ministerial departure.
And in around 11 weeks we have a referendum on our membership of the EU - a single vote on a critically important issue that will have massive potential impacts for decades into the future. That should not be held in the immediate aftermath of the turmoil of a prime ministerial resignation.
Yet it's clear that we now have a government on borrowed time.
Another of David Cameron's many problems is that he doesn't have a stable majority in parliament - that's been clear on the Sunday Trading Bill, on the Personal Independence Payment cuts, on the Human Rights Act.
And we've now got the unlikely champion of the people - the House of Lords - flexing its muscle. This week it's likely to be giving the government another bloody nose over the attempt to abolish social housing that is the Housing Bill.
And David Cameron's been presiding over a government that's clearly failed to be less than clear on issues far beyond financial holdings, and that's failing to deliver competent, effective government for the country.
Jeremy Hunt as Health Secretary has tried to impose a contract on the junior doctors that they clearly are not going to accept. He's headed the plan to abolish student nurse bursaries that threatens to enormously grow our already acute nursing shortage. And he's been exposed as a man who wants to transform healthcare from our much-loved free at the point of use to an American privatised system - which was not the policy the Tory party presented to voters at the last election.
Nicky Morgan as Education Secretary has continued the disastrous, damaging policies of Michael Gove, and gone further, planning to enforce the privatisation of our entire school system through forced academisation. Again, this was not a policy presented to the British people when they went to vote last year - there is no democratic mandate for it.
Iain Duncan Smith is presiding over the hideous - and possibly criminal - mistreatment of the most vulnerable in our society, with benefit sanctions and mismanagement of disability benefits now on an industrial scale, while there's no evidence that his grand plan of Universal Credit can even be delivered.
This is a government in turmoil - its head has lost the public's confidence, its policy programme has no legitimacy, it doesn't have a stable majority.
We need a new general election, but before we get to that we have to allow space for proper debate in other important elections and for the critical European decision to be made.
Then we can have a proper debate about the future of Britain - and elect a government that has the people's trust, and will implement the programme that it has offered to the people.
So Cameron, and Osborne, and Johnson, and May, have to go, but not quite yet.
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