It has not been Mr Cameron’s best week.

He should not have made self-righteous remarks about offshore trusts, knowing that he himself had previously benefited from one. (And anyhow, it is in fact perfectly legitimate to hold funds offshore so long as tax is duly paid on any money which is then brought into the UK.)

But when the Panama papers hit the press, he completely mishandled the ensuing media storm. His tax returns show that he is rich, lucky chap, and that he has duly paid his taxes rather more fully than he need. There is actually no law against being rich.

All of that came on top of a less-than-successful Budget Statement (again largely through poor presentation rather than content), and Tata pulling out of Port Talbot, timing its announcement unhelpfully to coincide with the Business Secretary’s perfectly legitimate trip to Australia. All of that is just mishandling, and unfortunate timing.

Much less forgivable was his disgraceful decision to use £9 million of taxpayers’ money to distribute a very dodgy dossier of pro-EU propaganda to every house in the UK. Those campaigning to stay in, and those hoping for Brexit, are both allowed to spend £7million on their campaigns.

This illicit leaflet was sneaked out before the campaign started so that it would not form part of the total. And the notion that it is purely factual, and answering a call from the electorate for more information about the EU, is simply laughable. I fear that it is a symptom of desperation.

The ‘In' campaign know that the result will be very tight indeed, with at least a real possibility of Brexit winning. They are ready to do anything to try to prevent that from happening. Abusing taxpayers' funds in this way should not have been allowed by the very careful civil servants who normally monitor such things. I hope that if it is not too late the leaflet will be recalled, and I suspect that the furore over it may well rebound against their pro-EU cause.

The sheer pressure of events and decisions that bear down upon a Prime Minister can on occasion mean failures of judgement of these kinds. He has not a second of the day without calls on his time and his thinking. The troubles of the nation and the world rest on his weary shoulders in a very real way.

That is why Prime Ministers need to realise that they cannot do it all themselves. They need the support of their Cabinet, their junior ministers, their backbenchers (who are too often forgotten about), their party in the wider nation and above all the electorate. Shut in their protective bunker in Downing Street, PMs who forget that risk paying a heavy price for it.

Mr Cameron will steady the boat, especially after the Referendum on June 23; and we all know that a Conservative government is greatly better than any alternative. Yet to do so, he must realise that he is not in it on his own, and that he needs his friends and supporters (and even more his enemies) in the same mule team.

He cannot afford too many Septimanae Horribilis such as this last one.