Business leaders' concern at the growing backlash against bankers was underscored on Friday when an array of senior figures called on Gordon Brown and other world leaders to use next week's G20 summit to pledge faith in the market economy.

Their intervention comes as London braces itself for anti-capitalist demonstrations timed to coincide with the meeting and ends a week in which windows were smashed at the Edinburgh home of Sir Fred Goodwin, former chief executive of Royal Bank of Scotland.

Richard Lambert, director-general of the CBI employers' organisation, said the anti-banker mood was turning into a “witch hunt” that could ultimately cost Britain foreign investment. Bankers had become a “convenient scapegoat” for politicians, regulators, central bankers and the media, he said.