Government, retailers and the food service industry have to "step up to the plate" to tackle the crisis facing the British farming industry, a farming group has said.
David Handley, of Farmers For Action, was speaking after an emergency summit to discuss falling milk, lamb and arable prices, held in central London.
The meeting follows days of protests by farmers including Milk Trolley Challenges, blockades at distribution centres and even bringing cattle into supermarkets.
Farmers estimate that it costs between 30 and 32p to produce a litre of milk but the average price paid across the UK is 23.66p - following a drop of 25% in a year.
Mr Handley told reporters: "There's a letter going out to all the retailers and I would say to government and the food service industry - they all have to step up to the plate.
"I don't think there's any farmer out there at the moment that will accept they can just sit back on their laurels.
"Peaceful protest has worked well so far, I think that will carry on until we can actually deliver something."
Earlier, the National Farmers Union (NFU) warned British-produced food could disappear from many supermarket shelves in months.
Speaking outside the summit, NFU president Meurig Raymond said: "Obviously the industry is in crisis. There's despair within our members.
"I've been farming for 45 years and this is the worst I've known, particularly the dairy sector and the lamb sector.
"We've seen a 30% fall in milk prices in the last 12 months and we've seen good quality new-season lamb being sold at least £15 per animal less than last year.
"It's a crisis I've haven't seen in my farming career."
Mr Raymond said many farmers faced "big decisions" in the next few months. "For lots of farmers there's a cash flow issue," he said. "They're finding it difficult to pay bills, the overdrafts are increasing. Unless things improve, they may well have to make some big decisions in the next couple of months."
The Milk Trolley Challenge sees farmers removing all cartons of milk from shops including Asda, Morrisons and Lidl before paying for it and taking it away, or dumping it at the checkout.
Mr Raymond said he was "delighted" British consumers appeared to be on the side of the farmers. He added: "I just plead with consumers at this time to look for Britishness, look for the Red Tractor, then they're guaranteed top quality assured food.
"If the farmers exit the industry, then British food may not be on the supermarket shelves in months and years to come."
Milk prices have been falling steadily - with Arla announcing a price cut of 0.8p per litre, taking the standard litre price to 23.01p for its UK members.
Farmers estimate that it costs between 30 and 32p to produce each litre of milk - meaning some are losing almost 10p per litre
A survey of milk drinkers found they would be willing to pay £1.28 for four pints of milk. Supermarket prices currently range from 89p to £1.
A spokeswoman for the Department for Environment, Food and Rural Affairs (Defra) said: "We maintain a regular dialogue with farming unions and industry. We look forward to discussing these issues with them further."
A British Retail Consortium spokesman said: "There is no connection between the price of milk in supermarkets and the price retailers pay farmers for their milk.
"The retail industry pays a fair price with individual retailers using different payment models. We understand the current frustration of farmers but it is wrong to blame retailers."