Wall Street golden boy Jamie Dimon today accused banks of giving customers “weapons of mass destruction” by loading them up with unaffordable debt.

“We gave them weapons of mass destruction to borrow too much,” he said, admitting that bankers did “some really stupid things” in the build-up to the credit crunch.

The chief executive of JPMorgan Chase, who has fared better than most in the crisis, also said his bank did not need to raise fresh funds and urged governments to stop talking about nationalisation. Speaking at the World Economic Forum in Davos, Switzerland, Dimon said: “JPMorgan would be fine if we stopped talking about the damn nationalisation of banks. We've got plenty of capital.”

He called on policymakers around the world to come together to solve the crisis gripping the financial markets and wider global economy.

“I just wish we'd get around to getting to it now,” he said. “I haven't yet seen people get all the right people in a room, close the damn door and come out with a solution.”

Dimon also hit out at the authorities who oversaw the borrowing binge, the collapse of the US subprime mortgage market and the global credit crunch.

“To policymakers, I say where were they?” he said, adding that the Basel II rules governing how much capital banks hold to back their loans “didn't work”.

He continued: “They approved all these banks. Now they're beating up on everyone, saying look at all these mistakes, and we're going to come and fix it.”

Losses and writedowns from the crisis have surpassed $1 trillion so far, forcing governments across the world, including in the US and UK, to inject cash into banks and tighten controls on the financial industry. JPMorgan Chase has weathered the storm better than other major institutions on both sides of the Atlantic such as Citigroup, Merrill Lynch, Lehman Brothers, UBS and Royal Bank of Scotland.

Under Dimon's guidance, JPMorgan Chase snapped up troubled Bear Stearns, and this month delivered fourth-quarter profits of $702 million in contrast to the multi-billion-dollar losses seen at competing banks.