Sterling tumbled to around $1.4865 during yesterday's session. It was trading in London at $1.4904 at 5pm last night, down from a pre-weekend level of $1.4920, having tumbled below $1.50 on Friday.
Ross Walker, UK economist at Royal Bank of Scotland, pointed out that anticipated US growth of around 1.9% this year was about double the forecast UK expansion in 2013. The UK is in danger of triple-dip recession, as its austerity programme continues.
Noting the pound had fallen to levels last seen in summer 2010, he said of the outlook for sterling: "We think it goes lower."
He noted RBS was forecasting the pound would fall to $1.46 by the middle of this year but cited the risks, given its recent sharp drop, sterling could fall below this level by then.
Mr Walker noted support for the dollar from strong US employment figures on Friday. And he believed the signals coming out from the Bank of England were weighing on sterling.
He said: "The Bank of England, although they insist they are not targeting the exchange rate, are doing nothing to stand in the way of its decline."
He added the Bank was doing nothing to indicate to markets it might intervene to support sterling at some point.