Britain’s PM Theresa May speaks outside 10 Downing Street after Parliament was dissolved ahead of the general election Picture: Reuters

Farmers and producers are facing a massive threat to exports after a British supermarket giant piled the pressure on competitors to not stock Irish beef.

Announcing it would sell only British fresh meat, the Co-op became the first retailer to push for a 'British-only' campaign. And the chain singled out Ireland as the "biggest beneficiary of EU meat trade with the UK", with £1.45bn (€1.65bn) of meat "arriving in the UK from across the Irish Sea".

Although the Co-op doesn't stock Irish beef, it called on other retailers to "back home-grown goods" from Britain.

Tesco and Sainsbury's are major stockists of Irish beef and any knock-on change of policy would be hugely damaging.

The move comes as relations between London and Brussels turned poisonous with British Prime Minister Theresa May accusing EU politicians of making "threats" to try to influence the UK's general election result.

Meanwhile, Ireland's Brexit concerns won't be allayed until a second phase of Brexit talks.

EU officials say clarity on customs checks for goods crossing the Border and other trade-related issues will take longer to achieve. And Dublin is ahead of Paris but losing out to Frankfurt in the bid to attract financial services firms looking to relocate from London after Brexit.

Irish Independent