Asda may have won our cheapest retailer award for the 11th consecutive year but its prices have increased more than any other retailer over the past 12 months, according to exclusive data from The Grocer.

The Grocer's extensive database, which collects hundreds of grocery prices every week, show Asda products climbed 13% in price, while Tesco is now 11% pricier. Morrisons' products are 10% higher, with Sainsbury's prices rising the least, by just 8%. The overall inflation figure is 10%.

Dairy products bore the brunt of soaring cost pressures with an 18.4% increase in price - higher than any other category. Asda's dairy aisle was up most, by 22%, while Sainsbury's and Tesco's rose least, by 15%.

Meat, fish and poultry climbed nearly as much at 17.5% . Tesco's meat aisle rocketed 23% - significantly higher than the other retailers - but Asda's increased the least, by 14%.

The next biggest rising category was bakery, with a 17% rise in inflation. The highest price rises were found at Sainsbury's, which recorded a 20% increase, while Morrisons' bakery aisles are 14% pricier.

And although the dairy and meat aisles witnessed the highest jump in prices, they were also the least likely to carry promotions.

"In an average basket of goods, 27% of the value spend consists of promotional offers. Dairy products generally only attracted 17% of promotions and bakery was close behind," said Mike Watkins, senior retail manager at Nielsen.

Darren Shirley, retail analyst at Shore Capital, didn't expect to see offers in the meat and bakery aisles any time soon. "Bread, milk and meat are high-volume lines. To put promos on these products would hit the bottom line, said Shirley. "While retailers are helping consumers with more cut-price deals, they won't cut their throats by reducing already unsteady margins."