Shoppers in the Republic of Ireland are still paying almost a fifth more than those in Northern Ireland, despite retailers’ price war.

A basket of groceries in Tesco costs on average 18% more in the South compared to the same products in the North, according to a study by Consumer Choice magazine.

The price difference for some items was as much as 37%, while 24 of the 25 items surveyed were more expensive in the Republic.

While Tesco accepted that the goods it sells in the Republic of Ireland are dearer than those in Northern Ireland, it said the average price difference was 12%, which it said was due to the higher costs involved with doing business in the Republic, as well as more expensive tax rates.

The Republic has been suffering from shoppers near the border making trips to the North to take advantage of the cheaper goods.

However, in May Tesco introduced a “change for good” price-cutting scheme in the South – prompting rivals to follow suit – which has alleviated the problem.

Before the so-called price war, reports suggested that there was a price gap of 30%.

There are worries however that any evidence that the price gap is still in place could reignite the cross-border shopping problem, just before the crucial Christmas trading period.