Home Secretary Jack Straw has revealed plans to stop paedophiles preying on youngsters in Internet chatrooms.

He wants to see "family friendly" ratings on websites, new laws to curb paedophiles from approaching children on the Net and child safety software installed and ready to go in new computers sold to families.

The proposed paedophile prevention orders would give the police new powers to stop sex offenders approaching young people over the Net.

The breach of an order would carry a maximum jail sentence of five years.

Mr Straw said: "Working with industry, childrens charities and with committed campaigners like Carol Vorderman, we want to make Britain the safest country in the world for children to use the web."

But shadow home secretary Ann Widdecombe said the new orders would be ineffective. She said a Conservative government would introduce a new offence of child "enticement", which would enable charges to be brought, whether or not there was an assault.

The Liberal Democrats said Labour's proposals should have been introduced "months ago" but claimed their were too few police officers to encorce the laws that already existed.