A nationwide Virgin Media print advert made the following claim: "Only three out of 10 homes in the UK can get 8Mbit/s or more over BT phone lines. Ten out of 10 homes with our fibre optic broadband can get 20Mbit/s."
Sky took offence at the claim, and complained to the ASA that the ad was misleading because Sky "did not believe there was sufficient capacity in Virgin's network to provide all customers with 20Mbit/s at the same time".
The ASA ruled that the comparison between the speed available on Virgin's service and the speed available over BT phone lines was "misleading and unfair" .
Virgin Media responded by claiming that any consumer confusion would be cleared up by some scrutiny of the small print in the ad, arguing that it had explained that actual speeds could vary.
However, the ASA felt that this too was misleading and "contradicted rather than qualified the strong implication of the headline claim that all customers on Virgin's cable broadband 20Mbit/s package would experience that speed".
The ASA agreed with Sky, ruling that the figures and speeds quoted were misleading to consumers, and that the advert should not appear again in its current form.
"Because we had not seen data demonstrating that all Virgin's 20Mbit/s cable broadband customers could achieve the headline speed in the home, we concluded that Virgin had not substantiated that claim," the watchdog said in its ruling.
Some parts of Atacama have not received rainfall for 500 years - but a sudden deluge of water upset the Desert's delicate biological balance
Spitzer Space Telescope could not spot Oumuamua, suggesting that it is actually pretty small
Greenland crater one of the 25 largest impact craters on Earth
This long-sought progenitor star was identified in an image captured by Hubble in 2007