While supermarkets are selling beef at an average of £5.62 per kg, the farmgate beef price has fallen 20p per kg over the past year, to an average of £2.62, according to the NFU.
The price farmers were receiving was unsustainable and producers had to be given a bigger share of the £3 margin if they were to continue in production, it said.
"If processors and retailers are serious about protecting the future viability of the UK beef industry they need to address the situation," said Alistair Mackintosh, chairman of the NFU livestock board.
Mackintosh acknowledged the UK was only 70% self-sufficient in the supply of beef but said that was no excuse for processors not to support British producers by buying the domestic product. "Why import more product and destroy confidence in domestic production when domestic production is more than capable of filling that void?"
Traditionally, Irish beef had been more competitively priced than British beef, being about 10 to 15 pence per kilo cheaper, but it was now on a par with British product, said Mackintosh. "We've heard from the processors about how important British supply is and how the consumer requires the product. In addition, support for the Red Tractor is stronger than ever. However, we're finding ourselves put under the cosh and supermarkets and processors have been using more Irish beef in the past 12 months than they did before."
Farmers also had a responsibility to stay aware of market conditions so that supply was more in line with demand, said Mackintosh.
Meanwhile, beef processor ABP has submitted plans for a multi-million pound expansion to its processing site at Ellesmere in Shropshire. The planned refurbishment would improve efficiency and reduce the plant's carbon footprint, it said