Internet service providers should offer a two-tier system, with users able to pick content suitable for adults or children, a Tory MP has said.
Mr Swire called for an "internet standards authority" to be set up
Hugo Swire said the "default" setting would be for children, with a password or PIN needed for unfiltered material.
A Whitehall department should create a blacklist of unsuitable sites, he said.
Home Office minister Vernon Coaker insisted the government was committed to protecting children, adding the internet was "safe" most of the time.
A task force set up in 2001 had been "a very successful method of bringing together departments, industry, law enforcement and charities", Mr Coaker - who chairs that group - said.
"I know how important it is to ensure that we remain ahead of the game when it comes to protecting children."
He said this was a "common goal" which was shared by MPs from all parties.
And he went on: "Today's children are sophisticated users of the internet and their knowledge of it is ever-evolving, but we should never forget that they are children."
Mr Swire called for a UK regulatory body for websites, which he dubbed the "internet standards authority", which would create the database of blacklisted sites and update this hourly.
This could work "along the lines of the Advertising Standards Authority or the Press Complaints Commission", and would be responsible for policing "harmful content" online.
Usage of social-networking sites had grown hugely, Mr Coaker said
Among the sites coming into this category would be "glorification of violence and terrorism, pornography, cyber-bullying, suicide, internet gambling and anorexia websites", Mr Swire added.
It has already been announced this week that an official Ministry of Justice review will look at websites which encourage suicide.
This is expected to include a look at the 14 suspected suicides of young people in the Brigend constituency in south Wales.
The local MP, Madeleine Moon, is due to hold a Commons debate on the issue on Thursday afternoon.
She has called for a national strategy on suicide and said she was worried that the rate of suicide was 35% higher in Wales than in England.