Warnings of a crash in oil production are no longer limited to a prescient few individuals - major British companies and oil CEOs are now sounding the alert

In the years approaching the credit crunch, whistleblowers were limited to a few insightful economists and financial journalists. Now whistles are blowing again about another grave threat to the global economy and the security of nations. They warn of an oil crunch: an unexpected crash in global production such that supply can no longer meet demand, even if China and India throttle back.

This time the warning is not limited to a prescient few individuals. Major British companies, led by Virgin, Scottish and Southern and Stagecoach, are flagging the danger, in today's report from the UK industry taskforce on peak oil and energy security . So too are the CEOs of oil companies themselves, in the case of Total and Petrobras, and growing numbers of other senior oil industry figures, usually recently retired. Even the International Energy Agency is sounding the alert, in a coded sort of way.