The ad uses graphic overlay technology to adapt the existing Henry V spot which uses the famous "Cry God for England, Harry and St George" line from Agincourt.
The spots have been booked into the half-time breaks of the England group games, within the LWT region. As the half-time whistle blows, a person at the London transmission centre will edit the ad to give England's current half-time score, which will appear under the "Whatever you do, take pride" strapline in the same font.
John Creedon, a client sales controller at Granada Enterprises, conceived the idea.
Creedon said the technology could also be used for providing editorial messages. "Using this new technology, we can now give advertisers with relatively small budgets the opportunity to use ITV1 creatively and make their ideas really stand out," he said.
Fuller's beer and brands director John Roberts added: "We want people to see London Pride as London's biggest rugby supporter. There is a perfect match between rugby fans and Pride drinkers - they are passionate about their subject, well informed and determined. Pride will own rugby during the World Cup and long after the teams have come home."