Britain's governing Conservative Party risks losing a traditionally reliable portion of the electorate with discontent spreading through the agriculture industry as the full impact of Brexit becomes clearer.

New trade deals that are perceived to be unhelpful for British agriculture, labor shortages because of changes to immigration policy, questions over revised food safety standards and the slow delivery of new financial support measures are major headaches for a section of the electorate that has traditionally been inclined to vote Conservative.

In her recent speech to the National Farmers' Union annual conference, union president Minette Batters called the mass culling of healthy pigs "an utter disgrace and a disaster for the pig industry", which was down to "the government's poorly designed change to immigration policy and what I can only say appears to be its total lack of understanding of how food production works and what it needs".

She also attacked the government for saying one thing and doing another, making it harder to hire staff and failing to help British farmers under new trade deals.

The 2016 Brexit referendum was not fought along party lines-then Conservative prime minister David Cameron backed the United Kingdom remaining in the European Union, whereas current prime minister Boris Johnson championed leaving.

In the run-up to the referendum, in an interview for the BBC program Countryfile specifically looking at the potential implications for agriculture, Johnson said leaving was the best thing for British farmers, and that any EU funding gaps would be filled by future governments.

"Our farming industry is vital to this country," he said. "It's vital to the way the countryside looks and feels, we need to support it. I think everyone understands it. It's an economic no-brainer."

However, the reality of what former business secretary Andrea Leadsom called the "sunlit uplands" of Brexit has turned out to be different.

Arable farmer Andrew Ward, a former Conservative voter, told the Financial Times he would be unlikely to do so at the next election, and that "every sector in agriculture is heading into a desperate situation" with the issue of subsidies, which see farmers paid for environmental land management measures, rather than using the land to grow crops as before, one of the main bones of contention.

"We were getting about 220 pounds ($291) a hectare (before the changes)," he said. "Now, one of the new schemes gives you 40 pounds and the other 70 pounds. It's just not enough."

The replacement of the old Ministry of Agriculture with the new Department for the Environment, Food and Rural Affairs is seen as having reduced farmers' voice in the political debate, as borne out in recent trade deals with Australia and New Zealand.

"As expected, this deal takes the same approach as the UK-Australia deal in eliminating tariffs for agricultural products, meaning that even for sensitive sectors like beef and lamb, dairy and horticulture, in time there will be no limit to the amount of goods New Zealand can export to the UK," said Batters when the New Zealand trade deal was announced.