Tim Berners-Lee, a computer scientist who invented the web 25 years ago, called for a bill of rights that would guarantee the independence of the internet and ensure users' privacy.
"If a company can control your access to the internet, if they can control which websites they go to, then they have tremendous control over your life," Berners-Lee said at the London "Web We Want" festival on the future of the internet.
"If a Government can block you going to, for example, the opposition's political pages, then they can give you a blinkered view of reality to keep themselves in power."
"Suddenly the power to abuse the open internet has become so tempting both for government and big companies."
Berners-Lee, 59, is director of the World Wide Web Consortium, a body which develops guidelines for the development of the internet.
He called for an internet version of the "Magna Carta", the 13th century English charter credited with guaranteeing basic rights and freedoms.