Former chancellor Ken Clarke accused US and European leaders of "paralysis" and playing "short-term politics" amid market panic about a fresh credit crunch.
As George Osborne and other finance ministers prepare for a crucial meeting in Poland, Mr Clarke warned that senior figures appeared "incapable" of dealing with the scale of the issues.
Stock markets staged a rally on Thursday after central banks announced a co-ordinated effort to shore up financial institutions with extra dollar liquidity.
The Bank of England, European Central Bank, Bank of Japan, US Federal Reserve and Swiss National Bank signalled they were ready to step in after French banks had their credit ratings downgraded due to concerns about exposure to an increasingly-likely debt default by Greece.
Shares in Britain's banks rose sharply on the news, with Lloyds Banking Group up 7% and Barclays, Royal Bank of Scotland and HSBC boosted 4%.
However, IMF managing director Christine Lagarde cautioned about a "lack of resolve" among politicians to tackle the longer-term problems.
And Mr Clarke - now the coalition's Justice Secretary - laid the blame squarely at the door of politicians.
"The main thing I take from this crisis is unfortunately the political leadership in the USA and large parts of Western Europe have been totally overwhelmed by the dimensions of the crisis, not able to cope," he told the BBC's Newsnight programme.
"You have paralysis in Washington, and paralysis in large parts of Europe because they are incapable of agreeing and everybody is fighting short term politics. I do not think the British government comes out of it too badly when you make the comparison. But our fate partly depends on how these people sort it out."
Mr Osborne is understood to agree with Mr Clarke's sentiments, although he is not expected to express his views so bluntly.