The government has rejected calls for greater web content monitoring in response to mounting pressure in the Commons for ISPs to be required to act as policemen.

Energy minister Malcolm Wicks said MPs should wait for the findings of a " convergence think tank" which the government has set up to examine the impact of convergence on the UK communications market ranging from broadcasting and telecommunications to "the online world".

He said a report, including any recommendations for legislation, should be delivered to the Departments for Business and Culture early next year.

Wicks was responding to a debate called by Glasgow Labour MP John Roberson to press the case for ISPs to be required to block material in breach of the law of which they have been notified regardless of where it is hosted.

Robertson complained that current law protects ISPs from liability for content except where it has been made aware of illegality and is storing the information through hosting or caching.

He said the Internet Watch Foundation (IWF) system failed even to act quickly to close down child porn, material inciting racial hatred hosted in the UK and criminally obscene material available worldwide, and and was too limited in scope.

He said: "While ISPs might not be responsible for producing and editing content that appears on their servers, they are the only ones with the power to deal with it, so why does the government not force them to do so with a licensing regime?"

Wicks defended the IWF as "a model of how self-regulation can work" and warned any extension to other areas would be less clear cut and open to legal challenge.

He added that "network-level blocking" in any event produced difficulties and revealed the Ministry of Justice "is looking urgently" at whether the law on matters such as suicide web sites can be strengthened and "will make an announcement shortly".