NI sales to Great Britain worth four times value of exports to Republic

However, sales of finished products to Great Britain relied upon cross-border trade in raw materials, the Office for National Statistics (ONS) noted.

The goods sold to Great Britain – classified as intra-regional trade within the UK rather than exports – were worth one and a half times the value of all Northern Ireland exports to the rest of the world.

Sales to the Republic accounted for 27% of the total value of declared Northern Ireland exports during 2016, narrowly ahead of the 25% exported to the United States.

The future of the Irish border is one of the most vexed issues facing Brexit negotiations in Brussels.

The ONS report said: “The sale of finished products to Great Britain relies upon cross-border trade in raw materials and components through integrated supply chains, meaning trade with both Great Britain and the Republic of Ireland are vital to Northern Ireland’s economy.”

It said further research was needed to investigate supply-chain links between Northern Ireland and Great Britain.

Food and live animals from Northern Ireland accounted for around 14% of total exports, much higher than the figure of 5% for the UK as a whole.

EU chief negotiator Michel Barnier has signalled a willingness to be flexible in Brexit negotiations around the Northern Ireland border.

Fears of a return to violence have been raised if the Good Friday Agreement is damaged by the imposition of a hard border on the island of Ireland after Brexit.

The EU’s suggested solution to the problem – a common regulatory area for goods and customs with the rest of the EU – has so far been rejected by the UK as “annexing” Northern Ireland.

• A no-deal Brexit scenario could decimate sheep farming in Northern Ireland, it has been claimed.

The costly tariffs arising from a lack of trade agreements could effectively price local lamb producers out of the vitally important French market.

Sam Chesney of the Ulster Farmers’ Union said the collapse of the loss of access to French consumers would be “devastating,” and could result in a large number of farmers turning away from sheep meat production.

“There would probably be very few sheep left in Northern Ireland, it’s as bad as that,” he told the BBC.

He said if sheep farming reduced it would have an impact on the environment in upland areas.

“The hills and the Glens of Antrim are shaped by the livestock on them. If they weren’t there, the hills would go to rack and ruin, it would be land abandonment really.”

A no-deal scenario, leading to EU tariffs, would make UK lamb products around half as expensive again for customers.

The UFU and the operators of Northern Ireland’s meat plants are calling for a trade agreement that would ensure a no-deal scenario is avoided.