Farmers are threatening to leave the industry following fears over the future of the Common Agricultural Policy, the president of the NFU has warned.
The growing dispute over the European Union finances had plunged the future of payments to farmers into doubt, Tim Bennett said.
Speaking to The Birmingham Post at the Royal Show which started yesterday, Mr Bennett said he feared farmers already struggling to adapt to radical reforms of the CAP may simply give up.
"The thing that worries me the most is that farming is going through the biggest changes since the Second World War and I have got people ringing me up to say they feel they may be wasting their time going on.
"We have farmers working their guts out trying to change and they are picking up this bombardment from the media that the Government wants serious CAP reforms. When you are already living through reforms they think why bother?
"These messages are very bad when we are dealing with farmers changing and investing in a new future and wondering whether it is worth bothering."
Mr Bennett, a first generation farmer who is originally from Halesowen, said he had had assurances from 10 Downing Street that further reforms of the CAP would not put British farmers at a disadvantage in the European market.
"Whatever happens in four to five, or more likely eight years time, it must be that we are not disadvantaged against European competition, and we have had assurances on that from them," he said.
Speculation that farming was taking a large proportion of the EU budget had been distorted, he said. Although he admitted France was receiving a higher percentage of the CAP cash, the CAP budget in the UK equates to just 0.2 per cent of the GDP.
Mr Bennett also called on the Government not to interfere with farmers and food production.
" The Government has involved itself in food production and this has stopped farmers from talking to consumers. Farmers have got to get used to understanding what consumers think and deliver what they want," he said.
Meanwhile EU Farming Commissioner Mariann Fischer Boel has called on the industry to raise awareness about CAP reforms.
She said: "Our politicians have been doing a very bad job. We have not been able to sell the CAP reforms to the public. We have not been able to tell people that these CAP reforms from 2003 were the most wide ranging reforms ever decided within agriculture.
"It is desperately important that there are farmers working to open up their farms, taking in children from schools and showing them what agriculture is like - they simply do not know anything and they think that milk comes from a milk bottle."