Frankfurt | It was supposed to be a drill. Government overseers would test whether European banks could survive a hypothetical perfect storm that included a steep economic downturn, plunging stock prices and a collapse in consumer spending.

But before bank regulators could begin their planned stress test this year, they were confronted with the real thing. The financial impact of the coronavirus — visible in shuttered factories, empty airports and desolate downtowns — makes their worst-case scenario, a 4.3 per cent decline in European Union economic output by the end of 2022, seem mild by comparison.