As the light faded during the Wimbledon men’s final last Sunday, the only thing illuminating the Nadal-Federer match seemed to be the London mayor’s distinctive blond hair. It would not have been out of character for Boris Johnson to pull focus in such an unintended way. The newly elected Conservative mayor of the capital had just experienced his most difficult week in the job yet. But might he have managed to mess up David Cameron’s year as well?

By the time the tennis finished, Johnson’s team had issued a press release effectively disowning Johnson’s first appointment as deputy mayor, Ray Lewis, after allegations surfaced over Lewis’s financial and s-xual behaviour while the Anglican parish priest of West Ham. Boris didn’t need the attention.

If Johnson had planned the week as it actually happened, his diary would have read: one, sack trusted Australian advisor James McGrath over comments about Afro-Caribbean immigration; two, announce that Ray Lewis is stepping down pending an internal inquiry; three, find out that father-in-law is dead; four, find out that Ray Lewis lied to everybody that he was once a magistrate; five, try to look inconspicuous at Wimbledon on Sunday so that the indefinite suspension of the Ray Lewis inquiry doesn’t get much press.

To understand why the Ray Lewis affair may yet destabilise the Conservatives nationally, one needs to recall how David Cameron won the party leadership in 2005.

Cameron’s Big Idea in making his party seem friendlier towards the disadvantaged was to use “the power and imagination of charities” instead of government agencies to deliver welfare services.

David Cameron publicly appeared with Ray Lewis numerous times when running for the Tory leadership and after his victory, holding Lewis up as an exemplar of his “let’s get the power of charity to do it” theme.

Ray Lewis comes from the east London borough of Newham, the impoverished area where the 2012 Olympics is to be based. He worked as a preacher in the Anglican church before ‘leaving’ to set up boot camps for troubled teens. He got the idea from watching Oprah Winfrey one afternoon.

When the mayoralty began to look winnable, the Boris Johnson for London Mayor campaign was effectively controlled by Cameron’s crew. Johnson’s first appointment was Ray Lewis. He was going to fix up London’s knife crime and teen violence. Johnson had campaigned relentlessly on teenage misbehaviour: it swung him the election.

Amazingly, though, nobody in the Conservatives remembered to dig up dirt for safety’s sake.

There are allegations of a s-xual nature while a priest, as well as allegations that he took £41k from three parishioners in Newham “to invest” and never gave the money back to them when requested. The Anglican church barred him from practising years ago. He also claimed – with Johnson repeating the claims during the mayoral campaign – that he worked as a magistrate. He has never held such a position.

The problem for Cameron is that his Big Idea to decentralise welfare services requires thousands of charismatic Ray Lewis types for it to work.

Yet daily, more lurid allegations surface about Ray Lewis and whether Johnson knew or didn’t know continue to roll out.

Labour does not look like it possesses the energy to capitalise upon these stumbles. When this story was leading the news, Gordon Brown pushed it second by telling Britons to save money during the credit crunch by eating leftovers.

David Cameron then made a speech telling the obese that they have only themselves to blame. What is the average overweight voter to do?

Ben Ellis is an Australian playwright.