A member of the Bank of England's monetary policy committee has defended pumping another £75bn into the financial system and said there was scope for a further round.

Martin Weale said that while central banks should not be seen as the solution to the world's problems, a third round of quantitative easing (QE) was possible.

His comments followed last week's decision by the Bank to boost its QE programme – in effect printing more cash – from £200bn to £275bn and hold interest rates at 0.5%. The move, dubbed QE2, is the first change to the programme since November 2009 and provided the clearest signal yet that the Bank thinks Britain is on the brink of a double-dip recession.

Speaking on Sky News today , Weale said that with interest rates so low, the Bank could still pump more cash into the system as it tried to stimulate economic growth. "There is quite a lot of scope for further quantitative easing," said Weale, who was head of the National Institute of Economic and Social Research before joining the MPC as an external member in August last year.

"Before the purchases we announced last week, the amount of government debt in the system was actually higher than it had been before the earlier bout of quantitative easing. There is quite a lot more that could be done but at the same time I think one has to recognise that central banks can't be expected on their own to resolve all of the world's problems."

Meanwhile, the former MPC hawk Andrew Sentance criticised the Bank governor, Mervyn King, saying that he was misleading the public by describing the current situation as the worst financial crisis the world had ever seen. "Members of the public do not make a clear distinction between the financial system and the economy as a whole and they may think he is saying this is the worst economic situation since the 1930s or before," Sentance told the Sunday Times. "I think this is very dangerous and it is misleading the public … What we need to do in the current environment is sustain consumer confidence."

He also repeated his view that QE would not help growth, saying "it risks sustaining the surge in inflation".

Weale denied further QE simply led to inflation without stimulating the economy, claiming the situation would be worse without it. But he acknowledged there was uncertainty about its impact:"I have not heard anyone suggesting that quantitative easing actually inhibits the growth of the economy, that it fails to provide support," he said. "Some people have suggested that it translates fairly directly into inflation without supporting economic growth, but I can't see any reason why that should be the case.

"I haven't heard of a convincing mechanism why that should be the case. So the further quantitative easing is to provide further support for the economy. Obviously the future is uncertain and we don't know how much support will be provided but I certainly think it is an appropriate response to a weakening economic [situation]."