Brexit could herald the end of the small family farm in Northern Ireland, Sinn Fein has warned.
The region's farming and agri-food industry would be devastated by tariffs and restrictions on movement across the Irish border, the republican party claimed as it launched a new policy document on the sector.
Euro MP Matt Carthy said the potential negative impact on farmers highlighted the need to attain special EU designated status for Northern Ireland when the rest of the UK leaves the EU.
He said European subsidies to the region's farmers, totalling £236 million a year through the Common Agricultural Policy (CAP), were unlikely to be maintained at the same level under a post-Brexit UK government.
"Irish agriculture operates much better when it is operating on an all-Ireland basis - it's too small a country to have farmers competing against each other on price and any barriers that are put in place will prove difficult," he said at an event at Enniskillen Farmers' Market.
"What special designated status means is that the North, to all intents and purposes, remains part of the EU - it remains part of the single market, the customs union and is able to draw down CAP funding into the future."
He also warned the region's market could be flooded with cheap unchecked imports if EU food safety regulations cease to apply.
Sinn Fein's Michelle Gildernew echoed her party colleague's comments.
"I think farming is going to be much less sustainable in Brexit, in fact we could see an end to the small family farm as we know it today," she said.
The former Stormont agriculture minister said those farmers who voted for Brexit had been "sold a pup" and "led down the garden path" by campaigners who asserted they would be freed from red tape.
"I think some farmers were convinced by political parties with a very narrow political agenda that they would be better off out of Europe and I think the realisation is coming home to them now that that is not the case," she said.