The German cut-price supermarket chain Lidl was accused yesterday of grossly mistreating staff at 200 of its stores by forcing them to do unpaid work, subjecting them to routine interrogations for suspected theft and refusing to allow cashiers to go to the lavatory...Lidl responded bitterly yesterday and claimed Verdi had mounted a campaign against the chain that was supported by "anonymous defamations". In a statement, Lidl said: "Given the rapid growth rate of the Lidl concern, it is unavoidable that in some exceptional cases, shop managers are employed who have weaknesses when it comes to dealing with staff."