The euro will not be around in the next 20 years, but Britain would have been better off had it joined the single European currency when it had a chance, legendary investor Jim Rogers told a British newspaper.

"Not being in the euro is a competitive disadvantage," Rogers told UK paper "Metro."

"It makes it more expensive and more cumbersome to do business with the rest of the world. But I am not sure the euro will last 20 years," he said. "The Italians and Germans will be in chaos because they have no plan B."

Also in the next 20 years China "may well be the largest economy in the world," Rogers said.

He reiterated his view that the pound will continue to weaken, as the City of London suffers because of the financial crisis and North Sea oil is drying up.

Britain is "a deeply indebted nation, the government is spending gigantic amounts of taxpayer money propping up banks which should have been allowed to fail," Rogers said. "If I was a British taxpayer I'd be totally outraged!"

He could not forecast an end for the economic troubles.

"We're certainly not out of whatever we're in and whatever we're in is getting worse," Rogers said.

For those worried about their future prospects, his advice was: "if you speak Chinese, go to China. Or try farming. I'm more optimistic about agriculture than any other industry. If not farming, anything to do with raw materials or natural resources."