Increases in energy and fuel costs coupled with seasonality issues have caused grocery prices to leap by just under 2% over the last six months. Latest data from The Grocer 100 reveals the average cost of our secret 100-item basket has risen by £3.16 since our End of Year Report in June and now costs £184.15.

The graph shows the impact of these rising costs on each individual retailer, as well as their positioning in relation to one another, which remains virtually unchanged from when we last reported on The Grocer 100's findings.

With an average basket price of £173.56, Asda remains the UK's cheapest supermarket for groceries and has extended its lead over nearest rival Tesco, which was 0.99% more expensive than Asda for the last six-month period.

Tesco was cheaper than Asda for a short period of time at the beginning of June, but has not managed to undercut its rival a single time since then.

In fact, Tesco appears to be having the hardest time of all the retailers in terms of reining in the effects of inflation. At £180.36, its most recent basket price is £7.52 more expensive than it was at the beginning of June, compared with Asda's hike of just 83p. Asda has adopted a particularly aggressive price-cutting stance over the last six months. Its basket hit an all-time low in June when at £169.49 it was almost 8% cheaper than the average.

The pricing gap between the top two appears to have widened in the run up to Christmas, a fact supported by The Grocer 33, where until this week Asda had provided the cheapest shopping basket for the last three reports.

The Grocer 100 data also reveals just how competitive Morrisons is becoming in terms of price.

The retailer is working hard to extend the gap between itself and Sainsbury's, and with an average basket price of £179.07 - £1.19 cheaper than Sainsbury's £180.26 - it's doing a pretty good job.

The retailer is working hard to keep a lid on inflation. The cost of its basket has gone up just 0.56% over the last six months compared with Sainsbury's where prices have been rising steadily, particularly since the beginning of September.

At 2.4% the retailer has incurred the second-largest increase in basket price since June, at £4.37.