In his maiden speech as an MP, Sajid Javid said that spending 19 years as an investment banker had “helped prepare me for a profession not well liked by the general public”.

As a newly promoted Treasury minister, he praised the City, which had made him a rich man, as one of “the best bits of capitalism”, judging people on merit regardless of background.

Yet there is a part of Javid’s career in global finance that he is less willing to discuss: his role working with the “timebombs” and “financial weapons of mass destruction” that helped cause the 2008 crash.

The descriptions are those of the legendary investor Warren Buffett; the products are derivatives, including collateralised debt obligations (CDOs) and collateralised loan obligations (CLOs) —