Downing Street's "e-petition" service, which allows the public to voice their concerns online to the prime minister, has received its millionth signature.
Downing Street website visitors can set up and sign petitions
More than 600,000 were for a petition calling for Tony Blair to scrap plans to replace road tax with pricing based on vehicle use.
The next most popular calls for the repeal of the Hunting Act.
Downing Street said e-petitions were "proving to be a popular way for people to get their views heard".
The service was launched three months ago, with more than 2,400 petitions being posted so far.
The anti-Hunting Act call has received almost 22,000 signatures, while a demand for a census to be published every 70 years - rather than 100 years - has gained 15,000.
A petition against introducing identity cards and one against replacing the UK's nuclear deterrent are also in the top 10.
A Downing Street spokesman said: "We welcome this landmark in our e-petitions service, which is proving to be a popular way for people to get their views heard.
"We look forward to further developing the service in the coming months to help citizens engage with the work of government."
Some petitions have been turned down because they are frivolous, inappropriate or in bad taste - but these are still listed on a separate section of the Number 10 website.
One demands: "Ban broccoli as an edible foodstuff and reclassify it as a toxic substance."
Another implores: "Let Big Al be a contestant in the Big Brother house."
There are also rejected calls to close down Arsenal Football Club and to "look at owners, not dogs".