As president of the Ulster Farmers’ Union (UFU), my last three years have been dominated by Brexit and what it means for farming families. More than 33 months on from the referendum all we have are unanswered questions and uncertainty.

The threat of a no deal is still there. Parliament’s vote to reject a no-deal Brexit, and to seek an extension to article 50, are positive steps but the legislation is clear. If the UK does not agree an exit deal with the EU, we leave with no deal. This is a terrifying prospect for Northern Ireland farming families and their businesses.

A no-deal Brexit would be a practical and logistical nightmare for our farm businesses. The no-deal tariff schedule, published by the UK government last week, gave an insight into what we are facing. A zero rate tariff on agricultural goods coming from the Republic of Ireland into Northern Ireland would decimate farming here. It offers Ireland a tariff-free backdoor into the British market. This would wipe out any post-Brexit home market dividend for Northern Ireland farmers.

Q&A What is a tariff? Show Hide Tariffs are border taxes charged on foreign imports. Importers pay them upon entry to the customs agency of the country or bloc imposing them. Tariffs can be levied in different ways. It can be a flat-rate tariff linked to weight, or calculated as a proportion of the overall value of the goods. It can also be a mixture of both. A country can set a quota, enabling a certain volume of a product to flow in before a higher tariff rate kicks in. Tariffs raise money for governments, but are primarily used to raise the price of foreign goods, protecting domestic producers from global competition.

Countries signed up to the World Trade Organization (WTO) must impose tariffs at the same level for all other WTO-member trading partners under the organisation’s “most favoured nation” rule – unless they secure alternative deals with particular countries or trading blocs. Richard Partington

They would then take a double hit, with the reduction in UK tariffs bringing a surge in food imports from across the globe. Many imports will be produced at a lower cost thanks to poorer environmental, animal welfare and labour standards. This would leave our farmers uncompetitive and priced out of our biggest market. To add insult to injury, Northern Ireland, and the rest of the UK, would inevitably face tariffs on exports to Ireland and the rest of the EU member states. This would close key and long-standing trade routes. It would put farming families out of business and destroy Northern Ireland’s agriculture industry.

From the outset of Brexit, I have argued that we must find a solution that allows long-standing trade relationships between Northern Ireland and Ireland to continue with minimal disruption. These are relationships that affect all of agriculture. They have been in place since long before the UK and Ireland joined the then EEC. That said, Great Britain is and will remain our main market – it is essential we continue to sell food unhindered into the rest of the UK.

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This is why the UFU supported the prime minister’s withdrawal agreement. If another option were on the table, it would be considered. However, at present, it is the only deal on offer. While there are still areas that need clarifying, overall, the document would secure Northern Ireland’s agricultural trading relationships. That has always been our key aim.

Regardless of the outcome of the third meaningful vote on the withdrawal deal, it is likely the EU will respond favourably to a request to extend article 50. Any extension must be used constructively and subsequent negotiations must have real substance. It is time to put differences aside and act in the interest of the country as a whole. The government and MPs must identify a clear strategy – simply delaying the prospect of a no deal is unacceptable.

The focus of the UFU has always been on what is best for agriculture and our members. Where possible, we steer well clear of mainstream political issues. With less than a fortnight to go to the deadline for the UK to leave the EU, my attention is firmly on what is best for the future of family farm businesses in Northern Ireland. I hope others can say the same and that this is reflected in the decisions they take in the coming days.

• Ivor Ferguson is president of the Ulster Farmers’ Union