A member of the public made the complaint last week, according to the ASA. The month-long campaign, which runs until January 28, bases the claim on figures from Hitwise that say Telegraph.co.uk was visited more times than any other newspaper website between July and September 2006, based on UK visits only.
However, both The Guardian and The Times contest the claim.
Hitwise collects data on the number of visits to certain URLs, rather than unique visitors, and the ranking referred only to UK visits to the homepages of the newspapers, not any of their extension brands or channels.
According to ABC Electronic, which audits website figures, The Guardian had 13.8m unique users in December 2006 compared with The Daily Telegraph's 6.4m. However, the figures do not show how many users were UK-based
A Telegraph Media Group spokesman said: "According to Hitwise, which measures the number of times a website is visited each month, Telegraph.co.uk is the number one quality newspaper website in the UK."
"We have not received any complaints about our current promotion from readers, users or any other interested party and we shall continue to offer the high quality of online content for which users return to us again and again."
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