They said it looked “ever more the likeliest outcome” that the UK would leave the EU without an agreement.
The government said leaving the EU with a deal remained its “top priority”.
“We are meeting weekly with representatives from our food and drink industry to help prepare for all scenarios,” said a spokesperson for the Department for Environment, Food and Rural Affairs.
But the food industry said the current situation was a “moment of potential crisis” for their industry.
Those signing the letter included the heads of the Food and Drink Federation, the National Farmers’ Union and UK Hospitality.
Members of the various trade bodies include Mondelez subsidiary Cadbury; KP Snacks, which makes Hula Hoops; and Butterkist popcorn, as well as consumer goods giant Nestle.
“Neither we nor our members have the physical resources nor organisational bandwidth to engage with and properly respond to non-Brexit related policy consultations or initiatives at this time,” they wrote.
“Government has recruited many extra staff; we cannot.”
The firms urge the government to place a range of current and planned industry consultations on “pause” until the Brexit uncertainty is over.
The consultations the firms cite include one relating to further curbs on the advertising of sugary foods, a national recycling collection strategy and proposals for a tax on plastic items with less than 30% recycled content.
The letter, first reported by Sky, is further evidence of the industry’s frustration at the continuing lack of certainty over the Brexit process.
“Businesses throughout the UK food chain – and their trade associations – are now totally focused on working to mitigate the catastrophic impact of a no-deal Brexit,” says the letter, which was sent last Friday.
“Large amounts of time, money, people and effort are being diverted to that end.”
The letter comes just two weeks after major retailers warned MPs that a no-deal Brexit would cause huge disruption to the industry, leading to higher prices and empty shelves in the short-term.
Sainsbury’s, Asda and McDonald’s were among those who warned stockpiling fresh food was impossible, and that the UK was very reliant on the EU for produce.