Guaranteed financial support from the EU to the UK's farmers means they have a better deal as part of the union, EU agriculture commissioner Phil Hogan said in Wales.
Welsh farmers gathered to hear the views of the Commissioner and UKIP MP Stuart Agnew, who also sits on the European Parliament’s Agricultural and Rural Affairs Committee.
Hogan has been in Northern Ireland trying to persuade farmers to vote to remain in the European Union.
Speaking about the payments made to those in the agricultural industry from the EU budget, he said there would be no guarantee that farmers would be able to get money elsewhere if the UK opted to leave.
"Welsh farmers appreciate the fact that they're part of a large European market of 500m customers."
"In the event of a Brexit, Wales like the rest of the UK would have to negotiate free trade agreements again. It would be quite an inconvenience."
'Time to depart the CAP'
Agnew, who produces free range eggs in East Anglia, said in February the UK would be better off out.
"The UK ran a huge trade deficit with the rest of the EU," he said.
He said that the Common Agricultural Policy had been generous to farmers between 1972 and 1984.
"Ever since then we have been on a steady downhill slide of increasing regulation, and the support for the industry is getting harder and harder for farmers to get at.
Referring to delays in the CAP: "We have had the best of it. It’s now time to depart the CAP.
"It’s not fit for purpose; 28 countries – you are going to north of the Arctic Circle with commercial reindeer farming, down to a Mediterranean island where people are following clapped out draft oxen with a wooden plough, or to here in the UK with 550 horsepower tractors. You cannot get a common market in that situation."
'EU supports family farming tradition'
Hogan spent time with farmers in County Down, Northern Ireland, taking questions from dairy, beef and sheep farmers.
"Whether they are dairy farms in Fermanagh or orchards in Armagh, the European Union has supported Northern Ireland’s family farming tradition and provided it with strong prospects for the future," said Mr Hogan.
"It offers the world’s largest agri-food markets, with exports exceeding €129 billion in 2015. In total, farmers in Northern Ireland have the opportunity to capitalise on over 53 trade agreements which allow for agri-produce to be exported and imported without any red tape.
"As part of our ongoing negotiations, we aim to establish new trading agreements which would enable all EU member states to extend their sales to other Asian markets.
"CAP Single Farm Payments to farmers in Northern Ireland is worth in excess of £2.3 billion from 2014-2020. To put that figure into perspective, annual payments from the European Union account for 87 per cent of annual farm incomes, compared to 53 per in the UK as a whole.
"In other words, for every £10 sterling that Northern Irish farmers earn, the Common Agricultural Policy accounts for £8.70 of that total," he said.
