Bank of England (BoE) governor Mervyn King sent sterling into a tailspin on Thursday (September 24th) after he declared that the central bank would be tolerant of a weaker exchange rate on the pound.In the statement, Mr King claimed: "The fall in the exchange rate that we have seen will be helpful, but there's no doubt that we need to see a shift of resources into net exports that compete with imports and help to reduce the trade deficit."Speaking to the Financial Times about the impact of the statement, foreign exchange specialist at Commersbank Ulrich Leuchtmann said that the BoE was putting the stability of the pound at risk by using its weakness as a tool to construct economic recovery in the UK.Following the announcement, sterling dropped to a fresh five-month low against the euro, while also weakening against the dollar after the publication of gloomy housing figures in the US.This morning, foreign exchange brokers were shortening yesterday's losses against the dollar, with many hopeful that the G-20 leaders will today make firm commitments to global economic stability.