An advert for TalkTalk Plus TV has been banned by the Advertising Standards Authority (ASA) following a complaint from Sky.
In the marketing content, TalkTalk claimed that its higher-tier broadband deal offered "Britain's best value unlimited TV broadband and phone".
The advert small print compared the broadband package to similar triple-play deals offered by BT, Sky and Virgin Media.
However, Sky took exception to the wording of the advert, arguing that it was potentially misleading to customers.
Sky believed the advert's claim was misleading because - in the context in which it was used - it implied that TalkTalk offered a product of "comparable quality" to the named competitors, but at a lower price.
The firm claimed that the words "unlimited TV" were larger than any others in the ad, giving the impression that TalkTalk Plus TV offered television services of at least comparable quality to the other deals mentioned.
However, Sky argued that this was not the case, since its own TV service includes 37 pay channels not available with the TalkTalk package, plus more than 200 free channels compared to TalkTalk's 74.
In its defence, TalkTalk considered that the claim "Britain's best value unlimited TV broadband and phone compared to Sky, Virgin and BT" would be viewed by consumers as relating only to the price of the various packages compared.
It said the advertising was aimed at people seeking a low cost package, and TalkTalk's focus on price was well understood. As such, the firm said the "best value" claim should have been interpreted to mean "cheapest".
However, the ASA pointed out that the main body of the ad placed greater prominence on the elements of the package itself, such as "unlimited TV".
"In that context, we considered that consumers would be likely to understand that price was only one aspect of the comparison being made by TalkTalk, and would consequently expect the TV, broadband and phone elements of the TalkTalk package to be comparable with those offered by Sky, Virgin and BT," the regulator stated.
"We understood that the TV element of Sky's triple-play package included significantly more channels than TalkTalk's, some of which were pay channels, and considered consumers were unlikely to regard that element of the two packages as comparable."
The ASA said that because the "best value" claim was not adequately qualified - to make clear it related to a comparison of package prices only - the advert was potentially misleading to members of the public.
As such, it ruled that the advert must not appear again in its current form. The regulator also instructed TalkTalk to make clear that any future "best value" claims relate to price alone.