A new front has opened up in the fierce supermarket turf war which has pitted the “Big Four” chains – Asda, Morrisons, Sainsbury’s and Tesco – against the upstart discounters Aldi and Lidl.

The battle has been at full tilt for years, but, as 2016 shows glimmers of the UK economy emerging from anaemic growth, some analysts believe that shoppers who have been deserting the traditional grocers in their droves over the last five years could finally start drifting back from the discounters, heralding yet another year of low prices.

Data published over the last two weeks showed that Morrisons, Sainsbury’s and Tesco all enjoyed a rise in Christmas sales for the first time in years, boosted by discounting of alcohol and vegetables. The exception was Asda where sales slumped 3.5 per cent over the festive period.

But whether these sales data are an indication that the mainstream supermarket groups have finally found a way to fight back against Aldi and Lidl remains to be seen, as is the question of whether customers lured away by the discounters will return as easily as they left.

The Big Four have been facing the greatest threat to their dominance for a generation since the financial crisis of 2008 as the German competitors ruthlessly cut into their market share.

In November, for the first time, the combined market share of the two challenger supermarket chains rose above 10 per cent: double their share three years ago.

While the Big Four still dominate grocery sales, they are closing down branches and shedding staff at almost the same rate that Aldi and Lidl are opening new stores.

While the traditional retailers are contracting, Aldi and Lidl have been storming ahead with spectacular growth last year of 22.6 per cent and 15.1 per cent respectively as they continue to muscle into their share of the UK’s £170 billion grocery market.

More than half of UK shoppers now visit a discount store at least once a month and the number of us using them to do our main weekly shop has more than doubled to above 12 per cent.

So what went wrong for the big chains and what has been the secret for success of the discounters?

Steve Burt, professor of retail and marketing at Stirling University, believes “patterns of grocery shopping are fragmenting” and that the discounters have benefited from a “perfect storm” of circumstances since the financial crisis which explains their spectacular growth.

The Great Recession made more people more price-sensitive at the same time as there was a trend towards people “shopping far less but more frequently”, Burt said.

The weekly shop, which in the nineties and noughties involved going to enormous supermarkets in out-of-town retail centres, has, according to Burt, been replaced by a move towards shopping more often at smaller convenience express stores.

The no-frills discounters were able to respond nimbly to this trend because of their smaller size, which allowed them to open branches quickly in suburbs close to where people live.

Burt recalls that when the German discounters launched in the UK in the nineties they were mostly sited in out-of-town retail parks along with large supermarkets.

The locational strategy then was to entice people shopping at the major supermarkets to drop by the discounters to top up with cheap product lines.

As the discounters moved out of retail parks towards the suburbs they improved the shopping experience, shedding the “cheap and cheerful stripped-down” image where products were sold direct from pallets, selling more fresh food and increasing choice. “There is now no stigma to shopping at Aldi or Lidl,” Burt said.

“A typical hypermarket would have between 25,000 and 35,000 product lines but that number has been going down,” he added. “When the discounters launched in the UK they typically had around 600 product lines but that has risen to over 1,000 now.

“It is this more limited range that allows them to keep their costs down and compete on price. The range might be limited but the quality is more often than not comparable.”

Greater choice and an emphasis on quality has been a particular theme for the discounters over the last 12 months, with luxury items such as lobster (selling at Lidl in the run-up to Christmas for just £4.99) and Wagyu beef being relatively recent additions to their product ranges.

Nevertheless, the German duo have remained true to their founding principal of mostly offering their own brands of goods with almost no premium-priced products.

That class-conscious Britain is still very much alive can be seen in the supermarkets we frequent: Asda and Morrisons have traditionally appealed to lower to middle class shoppers, the middle classes frequent Marks & Spencer while Waitrose sets out its stall for the upper middle classes.

But that social segregation is breaking down at Aldi and Lidl. Recent research from consulting firm Him! found that more than 31 per cent of Aldi and Lidl shoppers now come from the AB (upper class and middle class) demographic, up from 12 per cent three years ago.

Waitrose, which recently suffered its worst drop in Christmas sales for nearly a decade, last week fought back against Lidl and Aldi by launching its first value-focussed television ad campaign in years.

While the price war continues, the most obvious winners continue to be consumers who now have more choice than ever before as well as lower prices.