BT has welcomed a new report by Ofcom, which reveals that the broadband provider's superfast services are the most reliable on the market at peak times.
According to the telecoms industry regulator's latest study, there are major differences between the average speeds received by customers of some broadband providers.
It showed that people subscribing to BT's up to 38Mb services receive 91 per cent of the maximum connection speeds during peak times, while customers of Virgin Media's 30Mb service only receive 35 per cent of the maximum speed.
A spokesman for BT said the survey shows that its customers are getting faster speeds than ever before and that its fibre products provide the most reliable experience.
"It reveals our network is much more likely than Virgin's to deliver the same speeds in the evening peak times when people most value their connection. We are pleased that Ofcom noted that on some Virgin Media products up to two-thirds of customers saw a significant slowdown in speeds at peak times," the representative said.
However, of all the broadband packages included in the report, Virgin Media's up to 100Mb service came out on top in the speed stakes, with average actual speeds of 92.6Mb over a 24-hour period.
In response, Virgin Media said the report proves that its customers get the fastest broadband around, both at peak times and all day long.
"We always deliver speeds far closer to our headline claims than BT manages at any time of day so BT is right to point out their network's consistency - consistently failing to deliver what they promise."
The debate is likely to rage on, with BT pointing out that there was relatively little congestion in its fibre network in November 2012, when the report was carried out, with congestion levels much higher in Virgin Media's cable network during the same period.
BT said customers should be wary of fast headline speeds that often fall dramatically when most customers are online: "Virgin Media admits that it manages traffic by up to 75 per cent if customers use their broadband too much, unlike BT's new Totally Unlimited Broadband, which will never slow customers down."