Irish Farmers' Association National Livestock Chairman Angus Woods has said that decisions being taken right now in relation to tariffs on Irish exports to the UK after Brexit are a defining moment for Irish agriculture.
He said the Irish family farm model of agriculture will not survive the imposition of import tariffs on agriculture produce for the first time in over 200 years.
Under the proposals, the UK will not introduce any new check or controls on goods moving across the land border into Northern Ireland, but tariffs will be payable on goods moving from the EU into the rest of the UK via Northern Ireland.
Mr Woods said that exporting farm produce though the back door of Northern Ireland simply will not work as lots of our produce goes directly to the UK.
He also said that the uncertainty already caused by Brexit has already cost Irish farmers hundreds of millions of euro as cattle prices paid by the meat factories fell significantly after the Brexit referendum in 2016 and have remained weak since then.
Meanwhile, Meat Industry Ireland - the trade organisation representing meat factories - said the UK's proposals in relation to tariffs published this morning represent a massive threat to Irish meat exports to the UK, particularly for beef.
Director of Meat Industry Ireland Cormac Healy said that Irish beef exports to the UK would now face tariffs that will undermine the viability of trade and is also being presented with a very restrictive import quota regime.
Mr Healy said that with just 16 days from the prospect of a no-deal Brexit, meat processors are processing animals not knowing if the meat from those animals will be able to enter the UK market or, if it does, whether the value of the meat produced will be seriously devalued due to tariffs.
He said the UK proposals suggest tariffs ranging from about €1,500 per tonne of manufacturing beef to over €2,500 per tonne of steak exports.
The meat industry is also alarmed that the UK government is proposing zero tariff import quotas that fall massively short of existing beef imports volumes into the UK and that these quotas will be open to all global suppliers.
Mr Healy said that very quickly we can expect to see erosion of the Irish position in the UK market for both volume and value terms due to stiff competition from lower-priced beef from other regions of the world.
IFA President Joe Healy said: "Our most exposed sectors, particularly beef, simply will not survive the kind of tariffs being talked about.
"We export over 50% of our beef to the UK. If this is subject to tariffs, it will be a 'direct hit' of almost €800m on the sector."
Earlier, Mr Woods said Irish beef farmers have already been affected by price reductions over the uncertainty around access to the UK market after Brexit.
Speaking on RTÉ's Morning Ireland, Mr Woods said: "The idea that Irish farmers and businesses would be able to pay a tariff and compete with the likes of South American goods into the UK market just wouldn't work."
He said there is precedence for current quotas to be divided into previous use quotas, similar to what was used for the lamb quota coming from New Zealand.
Mr Woods added that beef farmers are in a difficult position because, he said, no effort has been made in risk management in the lead in to Brexit.
The Irish Cattle and Sheep Farmers Association said the impact of the proposed tariffs on the Irish beef sector "would be catastrophic".
The ICSA said if the charges are imposed, exports to the UK "would totally collapse overnight".
It said adding a tariff (53% of most 'favoured nation') would mean that "Irish beef would be too expensive a proposition for the British consumer".
The ICSA added: "Sheep exports would not be hit as bad, as France remains our largest market."
Meanwhile, the head of external affairs with the Federation of Small Business Northern Ireland said the UK’s tariff proposals would result in market distortion.
Roger Pollen said if Irish companies were able to access the UK market through Northern Ireland without any tariffs or penalties, it would put a huge pressure on infrastructure to respond to that demand.
He said that a very chaotic process appeared to be unfolding, adding that this was a UK proposal and it was unclear how the EU would respond.
Mr Pollen said, with agreement on both sides, it might be possible for such a proposal to work.
He said that there was not an awful lot that businesses in the North could do to further prepare for a no-deal Brexit but it is never too late to begin preparing.
Exporters should take proposals very seriously - IEA
Irish Exporters Association CEO Simon McKeever said exporters should take the new tariff proposals very seriously.
He said under the new plans the UK has allowed tariff free access for 87% of goods instead of the previous 80%, however, he said, this is still hitting a lot of the main Irish goods going directly into the UK, like dairy products such as butter.
Mr McKeever said capacity issues going into the North may arise and there could be creeping checks going across the border.
He warned that Irish goods could become less competitive and be substituted by cheap foods from the EU or the rest of the world, such as beef from South America and chicken from North America.
Mr McKeever said it is still unclear if the UK is allowed have a preferential rate for one part of the EU.
Following last night's vote on Brexit in the House of Commons, the Killybegs Fishermen's Organisation has said its members are in a heightened state of anxiety about what the UK's next steps might be.
CEO Seán O'Donoghue said that a disorderly Brexit would damage Irish fisheries irreparably.
In a statement issued this afternoon, Mr O'Donoghue said: "We've been beating this drum for a long time in stating that the seafood and fishing industries are uniquely exposed given the sharing of fishing grounds with the UK. The Department of the Taoiseach reiterated last night that all of the important commercial fish stocks which we rely on are shared with the UK and approximately one third of all landings of fish by Irish vessels come from UK waters.
"An orderly Brexit is imperative, otherwise we face chaos and conflict on the high seas in the very near future not to mention the major conflict issues around exports and landings. We cannot countenance this happening and in the event of 'no-deal Brexit', we must at a minimum, maintain the existing access and quota sharing arrangements until the end of 2019 as covered in the recent Commission's proposal," said Mr O'Donoghue.
"Whereas fish are mobile and know no borders nor bear any nationality, our trawlers don't have this luxury and must obey boundaries and exclusion zones. Our industry is standing on the edge of a precipice and everything that we have strived for and developed for generations is staring into the abyss.
"We've worked tirelessly on this for almost two years, we've achieved a great deal in terms of commitments in both the Withdrawal Agreement and Political Declaration only to be now faced with this latest shambles in Westminster.
"The situation is much too serious to be playing politics with the livelihoods of Irish fishermen."