To pardonable glee from the press, the new archbishop of Canterbury, Justin Welby, has got his crozier stuck in a cowpat, after suggesting that the Church of England could set up in business as rivals to payday lending firms. The church commissioners, who nurture the Church of England’s £5.5 billion-odd of assets, ‘manage a well-diversified investment portfolio’; in pursuit of this diversity they forked £75,000 to Wonga – generally seen as a ravenous great white among loan sharks, which last year was caught charging students interest at over 4200 per cent.

Still, seventy-five grand out of five and a half billion is barely a drop in the font.

And Welby has noted, reasonably enough, that morally we’re all in it up to our oxters anyway. Welby’s own pre-clerical career in the oil biz included five years with Elf Aquitaine, the petro-behemoth ‘at the heart of the French state for years’, as Loïk Le Floch-Prigent, Elf’s CEO during François Mitterrand’s epically venal presidency, put it at his corruption trial in 2003. Elf’s oil interests in the Congo were also central to Françafrique, the French state’s exploitation of sub-Saharan assets to enrich the metropole after the formal end of colonisation; profits were channelled into the slush fund used by Elf barons to bankroll French and African politicians. Elf also proved a less than deft investor, shredding $150 million in the ‘great oil sniffer’ scam of 1979.

In Welby (Eton and Oxbridge before he took to oil) the prime minister has created a primate in his own image. Welby has opposed the naming and shaming of high-rolling bankers as ‘lynch mobbish’. Usury is OK as long as it’s charged at a fair rate of extortion. And Welby’s proposal to sweat the C of E’s assets by rebranding its 16,000 churches as credit union branches surely incarnates Cameron’s big society project, even if the government itself has gone cold on it.

By his own account, Welby got through to Wonga’s head Errol Damelin by his fluency in talking shark: ‘We’re not in the business of trying to legislate you out of existence, we’re trying to compete you out of existence.' One reason why Wonga’s rates are high enough to leave someone who borrows money for a toothbrush with a debt the size of Greece’s is that the loans are unsecured. Not-for-profit credit unions look attractive but are under-capitalised and have to steer between charging usurious interest rates and covering uncollateralised bad debts.

Sharks are great survivors. Welby’s vision of a new and sleek breed of vegetarian shark fit to out-compete its entrail-ripping cousins seems as double-minded as the church itself is, in repudiating worldly goods while going on about God’s ‘kingdom’, ‘power’, ‘glory’, ‘riches’ etc. It remains to be seen if the enterprise will cover toxic debts by hiking up rates for virtuous repayers or by scooping that well-diversified investment portfolio. Will defaulters be met not with the loan firms’ tontons macoutes but with moral blackmail about improvidence? Will dog-collared lucre brokers quiz hapless proles about whether they’re going to blow their £50 loan on pious works or fags and be told, in response, to stick their queries up their chasuble?