According to a Reuters report, Jim Rogers, one of the world's best-known investors, said on Monday that the pound could fall near parity with the dollar in coming years given Britain's increasing debt and lack of economic growth drivers.
Rogers said last week the pound was "finished" and people should avoid investing in Britain, leading to a retort from Prime Minister Gordon Brown that economic policy would not be influenced by speculators.
Sterling weakened against the dollar on Monday to near a 23-year low of $1.35 reached on Friday.
Rogers was a co-founder along George Soros of the Quantum Fund, which made more than $1 billion betting against the pound in early 1990s and now is an independent investor based in Singapore.
The UK economy shrank at its fastest pace since 1980 in the three months prior to December. British policymakers seem content to let the pound drop to help exporters, and Brown has said the building blocks of recovery are in place.
"I'd like him to explain what they are," Rogers said, adding if this meant bailing out failing banks it would be a disaster, given Japan had tried that in the 1990s and was left struggling to recover with "zombie" banks. "Take the pain, clean out the assets and start again," Rogers advised. He said joining the euro could make Britain more competitive, but he did not have much long-term faith in that currency either. "I expect the euro won't be around in 20 years."