Wetherspoons has revealed a total of 66 members of staff have caught coronavirus since the pub chain reopened.
The company said it had reported 66 positive COVID-19 tests among its 41,564 employees since they returned to work from July.
It said those infected worked across a total of 50 pubs, while 811 of its branches had been free of coronavirus.
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The firm said most of the reported cases among employees had been mild or asymptomatic – and that 28 of the 66 had already returned to work, after self-isolating in accordance with medical guidelines.
And Tim Martin, founder and chairman of the group, said trading had been “very quiet” over the weekend, before the government tightened restrictions on larger social gatherings.
He dismissed earlier suggestions that larger groups may have flocked to the pub before the new “rule of six” came into force on Monday.
The restriction means people could face fines of up to £3,200 if they are involved in social gatherings of more than six people.
Mr Martin said: “Trade was very quiet over the weekend, as the public weighed up the evidence about the alleged dangers of going out – Wetherspoon sales were 22.5% below the equivalent Saturday last year.”
Trade groups, including the British Beer & Pub Association, say the new rule will hamper the recovery of hospitality firms without extended financial support for the sector.
And Mr Martin told investors on Monday that he believed the safety of pubs during the pandemic had been “widely misunderstood”.
He said around 32 million people had visited its pubs since they reopened their doors at the start of July.
Wetherspoons says it has invested around £15m in social distancing and hygiene measures.