Although the BBC traditionally does better when sporting events are simulcast with its commercial rival, the proportion of viewers has dramatically skewed in its favour.
Industry pundits have suggested the request by the chairmen of Football Association clubs to watch the BBC could be hurting ITV.
This move was taken as revenge for the way the ITV companies have treated Nationwide League division clubs since the collapse of the ITV Digital platform.
Several smaller clubs face financial ruin because of Carlton and Granada's refusal to pay ITV Digital's outstanding debts to the Football League.
During England's clash with Germany in the Euro 2000 tournament, the split between the two channels saw 13 million viewers watching the BBC, while six million viewed on ITV.
However, the figure has now shifted to a 4:1 ratio in favour of the BBC's coverage. During England's clash with Denmark, audiences peaked at 13.3 million on BBC, with only 3.6 million opting for ITV.
Chris Boothby, the broadcaster director at BBJ, said: "Traditionally dual viewing is about 2:1. Although part of the reason may be that the public turn to the BBC during national events, the chairmens' requests certainly can't have helped matters."
MediaVest's TV director, Kevin West, agrees. "The differential is disappointing, but advertisers have little choice because ITV is the only station with which we can get access to them. Some matches are proving to be poor value, he said.
However, when ITV is the only choice for football fans they will watch the channel rather than shun the game completely.
ITV is reporting major commercial benefits as England progresses through the tournament, boosted by a flurry of late money from the motor, beer and entertainment sectors.
The network has received some critical acclaim for its coverage of matches that are hosted by Des Lynam. "Gazza aside, ITV's presentation is quite good, Boothby said.