Wetherspoons founder Tim Martin has told staff to "go work at Tesco" instead as the pubs firm warned them they could face delays over pay.The company, which employs 40,000 people, shut all its pubs on Friday after Prime Minister Boris Johnson ordered sites to shut until further notice in response to the coronavirus crisis.In a video message to staff, Martin suggested they could find employment at supermarkets while the chain's pubs remain shut.He said the group will pay employees for all work done until the pubs last opened, but will not make any further payments to staff until the Government fulfils its promise to cover 80% of the wages of workers affected by the Covid-19 shutdown.The firm's founder – who was a prominent cheerleader for