A basket of 35 commonly bought grocery items cost 83.33 pounds ($102.4) in December, mySupermarket.com said on Tuesday, up from 83.18 in November. The rise was driven by higher prices for fresh items such as bananas, grapes and carrots, it said.

Overall, the basket was still nearly 3 percent cheaper than it was in December 2015, the company said, as big retailers such as Tesco (>> Tesco PLC), Asda (>> Wal-Mart Stores, Inc.) and Sainsbury's (>> J Sainsbury plc) battle for shoppers.

Economists and retail experts expect inflation to creep into the UK market after last year's vote to leave the European Union caused a steep drop in the value of the British currency, making imported goods more expensive.

"Despite a rise in December, our Groceries Tracker Basket costs less in December compared to January and shows how the highly competitive price wars between retailers has helped protect shoppers from any subsequent rises caused by current affairs," said mySupermarket CEO Gilad Simhony in a statement.

The tracker covers nearly 5,000 products across supermarkets Tesco, Asda, Aldi [ALDIEI.UL], Sainsbury's, Ocado (>> Ocado Group PLC), Lidl [LIDUK.UL] and Morrisons (>> WM Morrison Supermarkets PLC).

(Reporting by Martinne Geller; editing by Susan Thomas)