CONSPIRACY theories are generally a diversion from the hard work of understanding class society and waging class struggle.

Most “conspiracies” overlook the organic nature of the development of capitalism and imperialism and replace class politics with the machinations of shadowy cabals.

However, sometimes powerful people do conspire. And sometimes their conduct passes beyond any attempt to accommodate it within a rational framework.

So to Morgan McSweeney’s phone. Parliament determined last month that all government communications relating to Peter Mandelson’s disastrous appointment as ambassador to Washington in December 2024 be made public.

That is to allow voters to understand how this first-order misjudgement, naming to the country’s most prestigious diplomatic post a man famous for his overaffection for the rich, twice dismissed from government amid scandal, and most importantly known for his prolonged intimacy with paedophile financier Jeffrey Epstein.

The release of documents and messages has been slowed by police wishing to avoid prejudicing their own investigation into Mandelson’s alleged misdeeds. This has led to the arrest of the ex-peer on charges which he denies.

No communications are likely to have been more relevant to the appointment than those from and to McSweeney, then Downing Street chief of staff, effectively running the government as top aide to the ineffectual Keir Starmer.

McSweeney was mentored by Mandelson as a close associate in Labour’s unending factional wars, with the younger man carrying forward the latter’s obsessive hatred of the left and socialism.

It is clear that he was instrumental in pushing Keir Starmer to name Mandelson to Washington. It is believed that he was charged with asking the now-disgraced New Labour grandee about his relationship with Epstein.

While the Prime Minister bears the responsibility, it appears that this was a calamity engineered largely by McSweeney, whose messages on the subject would therefore be central to any understanding of it.

Yet it is now unclear if we will ever read them. Now, McSweeney announces that his mobile phone was stolen in London last year, a month after Mandelson’s enforced departure from Washington and when it was already highly likely that some form of public accounting for the misjudgement would follow.

The police concur that McSweeney reported the theft at the time it apparently occurred. Giving an incorrect location, and then asserting that he was near a park in east London when he was in fact miles away in Westminster may perhaps be attributable to the stress of the moment.

Failing to advise the police that he was the No 10 chief of staff, and that his device held any number of secret communications of state significance is far less comprehensible, since that omission must have downgraded the police response.

Still odder, No 10 is unable to confirm that the contents of McSweeney’s phone have been fully backed up in line with government regulations for handling official business.

So on this occasion, the stench of cover-up is powerful, however much Starmer may deny it.

It is made the more rank by the fact that we are dealing with a man whose history inspires no confidence.

McSweeney engineered Starmer’s election as Labour leader in 2024 on a deliberately fraudulent prospectus, seeking to convince Labour’s membership that he was something he was not, the culmination of a plot matured over years.

He also ran the Labour Together factional campaign when it broke the law by failing to declare donations to the Election Commission, despite reminders, a breach that some have argued could hardly be accidental.

So the public will take some convincing that this convenient phone theft is as presented. It looks like the latest cover-up from professional practitioners of scandal.