Exports from Great Britain to Ireland fell by almost GBP2.5bn in the first seven months of the year with Brexit emerging as a major factor, according to official Irish government data.

The figures from Ireland’s Central Statistics Office (CSO) come just days after Marks & Spencer said it was scrapping 800 product lines from its stores in the republic of Ireland because of “excessive paperwork” and health controls on food.

The CSO recorded the value of goods imported from Great Britain for January to July 2021 as EUR6.3bn (GBP5.4bn), a 32% decrease year on year, equivalent to EUR2.9bn in sales compared with the same period in 2020.

Imports in July alone were also down 32% compared with the same month in 2020, with the largest decrease seen in food and live animals.

These categories of goods have all been subject to new physical and documentary controls on entry to Ireland since Brexit came into force in January.

However goods travelling in the other direction are not subjected to the same controls with the government last week announcing that checks due to be implemented in October and January would be delayed by up to nine months.

The asymmetrical trading relationship now appears to be translating into visible wins and losses. Sales rocketed for Irish traders by almost GBP500m year on year, up 60% (EUR567m) in July to EUR1.5bn, and up 26% in the first seven months of the year.

The largest increases in sales to Great Britain were in the chemicals and related products sector, which is not yet subjected to the stringent regulatory controls on entering Great Britain.

M&S last week blamed “pointless” paperwork for exports into France and Ireland, announcing it was closing 11 of its French stores because of problems supplying them with fresh produce since Brexit. It has said it will now try to source more product locally in Ireland, a strategy successfully deployed for the last decade by Aldi and Lidl in Ireland.

The UK government said it was postponing checks on British borders because of the pandemic and global supply chain issues. But border posts were not ready with work not yet started at either Dover in England or Holyhead in Wales, the two main gateways into the UK.

The UK recently chose a site for its border-control post at Parc Cybi in Holyhead in Anglesey, Wales, but on Monday it was clear work had not yet started.