US President Barack Obama would be granted powers to seize control of and even shut down the internet under a new bill that describes the global internet as a US "national asset".

Local lobby groups and academics have rounded on the plan, saying that, rather than combat terrorists, it would actually do them "the biggest favour ever" by terrorising the rest of the world, which is now heavily reliant on cyberspace.

The proposed legislation, introduced into the US Senate by independent senator Joe Lieberman, who is chairman of the US Homeland Security committee, seeks to grant the President broad emergency powers over the internet in times of national emergency.

Titled "Protecting Cyberspace as a National Asset Act", the bill stipulates any internet firms and providers must "immediately comply with any emergency measure or action developed" by a new section of the US Department of Homeland Security, dubbed the "National Centre for Cybersecurity and Communications".