Around 80 per cent of Portuguese companies still operating or temporarily shut due to the coronavirus outbreak reported a sharp drop in their revenues, at times exceeding 75pc, as authorities tightened lockdowns, a survey showed on Tuesday.

Around 78pc of businesses blamed the revenue free-fall on restrictions implemented by Portugal's Socialist government as part of a state of emergency to contain the spread of the coronavirus.

The emergency was initially declared on March 18 but is set to be extended until May 1.