Sales at the UK’s leading supermarkets rose by the highest year-on-year rate for over six months in January, against a backdrop of continuing inflation, according to new Nielsen figures.

Shoppers spent 4.2% more on groceries during the four weeks ending 27 January versus the same period a year ago. It was the highest year-on-year growth since a 5.1% rise in July 2017, following a short heatwave.

Excluding the discounters, sales rose 2.7%, while volumes only rose 0.1%.

“Inflation and New Year’s eve falling within the reporting period - which benefited alcohol (spend up 10%) and soft drinks (8%) in particular - helped supermarkets start 2018 in an encouraging fashion, following an extremely good Christmas,” said Mike Watkins, Nielsen’s UK head of retailer insight.

“This offset the fact that most of the major supermarkets saw less visits than a year ago as shoppers are still in an economising mood and may have cut back on restocking the cupboards with household bills coming in after Christmas. Furthermore, half of those who have changed their shopping behaviour are switching to cheaper grocery brands.”

Over the 12 weeks ending 27 January, Tesco had the most improved year-on-year performance among the big four (sales up 3.4%), followed by Asda (2.5%).

Lidl enjoyed year-on-year sales growth of 17.2%, with its market share rising from 4.6% to 5.2%, while Aldi’s sales increased by 12.6% and its market share by 0.6% to 7.8%.