Asda is the UK's cheapest supermarket for the 13th year in a row.

It obliterated the competition by offering the lowest basket 43 weeks out of 50 and picked up The Grocer 33 award for availability into the bargain at Wednesday's Grocer Gold Awards.

Over the past year, according to our end-of-year review of The Grocer 33, a loyal Asda shopper who had bought The Grocer's randomly selected basket of 33 items each week would have saved £65.14 on their grocery bills compared with an identical basket of goods at Tesco, £96.87 versus Morrisons, and £143.84 versus Sainsbury's.

And despite the launch of its Essential range, the premium for shopping at Waitrose was £531.75 annually, a £56.15 increase on the price differential in 2009.

"Winning on both price and availability is testament to the hard work and dedication the Asda team put into lowering prices on a broad range of products, without compromising on quality," said Asda CEO Andy Clarke.

"The launch of the Asda Price Guarantee earlier this year reassured shoppers we are the lowest-priced supermarket, but it doesn't stop there for us our mission is to leverage Walmart's global scale to continue to lower prices even further for customers."

The race for the availability award was more closely fought. Asda beat Tesco by just two out-of-stock items across the entire year to finish with 97.3%. Tesco improved its availability the most to come an excrutiatingly close second with 97.2%, after having the worst availability last year. And it also recorded the most full baskets, at 12, while Asda had the least, at four.

"Availability has improved as a result of initiatives to improve stock management, including more efficient ordering systems, a greater focus on clearing promotional and discontinued lines, better in-store monitoring processes and storing stock on the top of shelves on the shop floor rather than in the warehouse," said a Tesco spokesman.

Waitrose won on customer service after notching up 14 store of the week awards. Asda won 12 times, Morrisons nine, Tesco eight and Sainsbury's had the fewest wins with seven but Sainsbury's Simon Ross won the Store Manager of the Year award at the ceremony.

Waitrose also recorded the shortest queue time and was the only supermarket to average under five minutes spent queuing and scanning each week. Tesco's tills were the slowest, a minute and a quarter longer than at Waitrose. This means a shopper buying a 33-item basket each week would spend an hour longer queuing at Tesco than if they had shopped at Waitrose over the year.

The grocer 33 annual review totals

More expensive than Asda
Tesco £65.14 (£92.28 last year)
Morrisons £96.87 (£67.31)
Sainsbury's £143.84 (£145.70)
Waitrose £531.75 (£475.56)

Number of full baskets
Tesco 12
Morrisons 9
Waitrose 9
Sainsbury's 8
Asda 4

Asda 43
Tesco 45
Sainsbury's 51
Morrisons 52
Waitrose 62

Time at till
Waitrose 223 mins
Asda 258 mins
Morrisons 267 mins
Sainsbury's 279 mins
Tesco 285 mins

Read more
Asda 'guarantees' lowest prices with online shopping tool (28 April 2010)