The European Central Bank unveiled a new €750bn ($818.7bn) bond-buying programme aimed at shielding the eurozone economy from the spreading coronavirus, casting aside longstanding taboos to send a determined signal to investors that the bank will stand behind the region’s embattled governments.

The unexpected move, following days of delay and mixed messages from the ECB, underscores the high level of urgency among policy makers in Europe, which has emerged as the new centre of the fast-moving global crisis.