Waitrose boss Rupert Thomas has called for 70,000 British fruit pickers to come forward to prevent hundreds of thousands of tons of produce from rotting.
The supermarket's director of trading has issued the stark warning ahead of the British berry picking season next month.
He told the Daily Mail that Britain needed to invoke the spirit of the Land Army, the name given to the 80,000 Britons who brought in the harvest during the Second World War.
The COVID-19 pandemic has left British fruit and vegetable farms without 90% of their workforce, which is made up of migrant labourers, many from Eastern Europe.
Each summer around 70,000 seasonal workers normally arrive in the UK to work on farms – often staying in mobile homes and temporary accommodation on site for the duration of the picking season.
Thomas said: "We don't have enough pickers for harvest season and if we don't find people in time, hundreds of thousands of tons of wonderful, healthy British produce will go to waste and the livelihoods of countless British producers will be put at risk.
"Crops will, quite literally, rot in the fields without committed pickers. Truly, your country needs you."
Last month Ocado chairman and former M&S boss Lord Stuart Rose made similar efforts to mobilise tens of thousands of British workers.
He called on young people and university students to volunteer their services to help prevent gaps in shop shelves and prices rocketing.
Lockdown measures across Europe mean that migrant workers, many from Romania and Bulgaria, will be prevented from travelling to the UK.
Rose said the first crops of strawberries, seasonal fruits, and salads would soon be ready to pick.
He told The Mail on Sunday: "If those crops aren't picked, the crops will rot and that will mean there will be a shortage of fresh produce. There is nothing to guarantee the shortfall could be made up of European imports and even if it could, there'll be a cost attached."
Famers have also told of worries that the cancellation of outdoor events such as Wimbledon and weddings will create a berry glut. The Financial Times reported that British public are being urged to binge on strawberries to make up for what would usually be consumed.