It’s a big week for pivotal rulings on misleading claims.

And while the advertising watchdog’s verdict on the price war between Tesco and Aldi might not be quite up there with the ongoing drama at the Supreme Court, it too makes for fascinating viewing.

When The Grocer first revealed a new chapter in the price war between the UK’s biggest retailer and its discount rivals, in October last year, our coverage certainly touched a raw nerve with both sides.

At the time Tesco boss Dave Lewis had claimed Tesco was “not just price-matching but price-beating” the discounters, a claim that got both Aldi and Lidl hot under the collar.

When pushed by The Grocer, Tesco stressed it was not trying to claim it was cheaper overall than the discounters but that its Exclusively at Tesco own-label relaunch had changed the pricing landscape at the entry level. It was time to start shouting about it, it said.

Cue the start of a tit-for-tat battle in the press and on TV, which has not only helped Tesco regain its crown as one of the UK’s big advertising spenders, but must have been manna from heaven for hard-pressed media commercial teams.

Until today, Tesco has had the upper hand amid the discounters’ protests that its price claims were a bluff.

Just last week it successfully argued to have an Iceland ad banned over “misleading” price comparisons. And in the previous two months, Tesco complaints about ads from Aldi and Lidl had been upheld.

However, today the ASA ruled Tesco’s series of press and TV ads – which featured trolley and basket loads Tesco claimed were cheaper than Aldi’s or Lidl’s – were misleading, after Aldi launched a complaint about the ad blitz.

Can Tesco really convince consumers it’s cheaper than Aldi and Lidl?

Yet the ruling is not quite the defeat for Lewis it may seem.

Not only were two other claims by Aldi – namely that Tesco’s price-checking methodology was flawed and that the comparisons were not like-for-like – thrown out, but the ASA also found that the Tesco own-brand products featured in the ads were indeed cheaper than at Aldi.

The reason Tesco was found in breach was because such products were, in the words of the ASA, “not widely available throughout Tesco stores”.

This is significant because it surely vindicates a campaign that, when it was first launched by Lewis, had worried some Tesco shareholders, who feared it could be on the verge of a damaging price war against his discounter rivals.

Instead, Tesco has put its own-brand relaunch front and centre of its 100th anniversary price-cut campaigns. It has managed to raise its profile, both when it comes to price competitiveness and quality perception, while holding back from a suicidal all-out conflict it surely could not win. It even got away with putting thousands of prices up across the rest of the store, without any obvious sign of a consumer backlash. 

Of course, the fact that Exclusively at Tesco is not available at Express or Metro stores is an issue. Tesco has admitted it has a major job on its hands to restructure these stores to maximise their appeal to shoppers looking for convenience and price, especially the increasingly out-of-kilter Metro lineup.

But for the ASA to conclude Exclusively at Tesco is cheaper than Aldi… surely that’s a new ad slogan for Lewis, ready-made.