There may have been a sustained battle on pricing and promotions between the major retailers this year, but it's been a one-sided one.

Asda has increased its lead as the UK's cheapest grocery retailer in The Grocer 33 six-month review and is also on track to win the annual service award, with eight top store awards so far this year.

Last year, Asda's northern rival Morrisons closed the average gap in weekly basket price to just 98p thanks to its sustained weekend promotional blitzes.

But this Christmas, Morrisons has been relegated to third place, Tesco grabbing the second spot, with a basket an average £1.54 a week more expensive than Asda's. Morrisons was on average 54p pricier than Tesco, with an average weekly shop costing £53.65, while Sainsbury's £54.65 shop was the most expensive of the big four.

Waitrose remained the most expensive retailer in The Grocer 33 this year and despite the high-profile launch of its new budget tier, the Essential range, its price premium grew. Last year, shopping at Waitrose cost on average 17.2% more than cheapest retailer Asda, but this year it was 21.8% pricier.

Despite this, the average basket price at Waitrose and all of the big four retailers was cheaper in the second half of 2009 than in the same period last year. The average basket price this year was 4.6% lower than last year's £57.87 typical shop. Tesco saw the most dramatic drop in pricing, down 6.4% on the second half of 2008, while Waitrose saw the smallest decline, at a still solid 2.3%.

Pricing was not the only area where the supermarkets improved their offer to consumers: queue lengths fell and availability improved. The typical time spent at the checkout in the past six months was nine seconds shorter than the same time last year, saving shoppers enough time over six months to make themselves an extra cuppa back home.

Waitrose was by far the best retailer for queue time, its shoppers spending 18 seconds a week less at the till than those at nearest rival Morrisons. Tesco was the only retailer to buck the trend, slumping from first place last year to last place so far this year, as average queue times jumped a massive one minute 13 seconds each week.

Asda: 97.9%
Tesco: 97.6%
Waitrose: 97.4%
Morrisons: 97.3%
Sainsbury's: 96.9%