After last week's chaos, the euro continued to test new lows against the dollar, sterling and other major non euro-zone currencies until ECB president Wim Duisenberg's surprise intervention yesterday. That effort to reassure the public saw the currency regain the 89 US cent mark.

Mr Duisenberg and the euro zone's political masters will have to hope his reassurance works as one of the other options to restore confidence in the European Central Bank appears to be receding. Jean Claude Trichet, the governor of the Bank of France who was supposed to replace Mr Duisenberg as ECB president mid-term, finds himself embroiled in an investigation into financial irregularities involving Credit Lyonnais.

It seems unthinkable that anyone with a tarnished image will be seen as able to restore confidence in the euro and the monetary union project of which it is an intrinsic part.