Once an oil executive, the Bishop of Durham Justin Welby has become a trenchant critic of what he considers the excesses of capitalism. And now he has one of the biggest bully pulpits in England — he’s been named the new Archbishop of Canterbury.

He’s the first Archbishop to know as much about derivatives as divinity, and some critical of businesses believe they’ve found a powerful new ally.

“He’s not some naïve, ethereal figure,” says Luke Hidyard, who campaigns against corporate greed. “He knows what he’s talking about. It would be very difficult for big business to dismiss his concern.”

Welby has made his concern about corporate malfeasance very clear. He says shareholders should suffer dividend cut if their companies commit a crime. He’s railed against what he calls “ sinful corporations.” And he’s been critical of banks.

“He seems to feel that much of what bankers do these days is of no social value,” says Ed Haddas of the financial website Breaking Views. “So I think he’s going to be a pretty formidable opponent to the weak spots of the banking industry.”

But Brian Mairs of the British Banking Association does not feel threatened.

“Constructive criticism from somebody who’s actually been in there and understands how the markets work  could be very enlightening,” Mairs says. “We welcome the appointment.”

He may come to regard the Archbishop as a mixed blessing. One of the most famous Archbishops of Canterbury was described as “that troublesome priest.” And while Justin Welby is no Thomas Becket, history may be about to repeat itself.