A legally enforceable cinema-style classification system is to be introduced for video games in an effort to keep children from playing damaging games unsuitable for their age, the Guardian has learned. Under the proposals, it would be illegal for shops to sell classified games to a child below the recommended age.

At present only games showing sex or "gross" violence to humans or animals require age limits. That leaves up to 90% of games on the market , many of which portray weapons, martial arts and extreme combat, free from statutory labelling.

Ministers are also expected to advise parents to keep computers and games consoles away from children's bedrooms as much as possible, and ask them to play games in living rooms or kitchens facing outward so carers can see what is being played.

Ministers are also expected to recommend blocking mechanisms to protect children from seeing unsuitable games, emails or internet sites. Discussions have already been held with internet service providers to see if an agreement on a standardised filter can be reached.

A review of violence and video games has been commissioned by Gordon Brown from the former television psychologist Tanya Byron. She is officially due to report next month, but education and culture ministers have a sense of the report's direction. She has previously said she would examine the current classification system to see if it is confusing for parents.

The report's contents, which include a lengthy review of the literature on the impact of video games on children, has been discussed between the Department for Children, Schools and Families and the Department for Culture, Media and Sport. Ministers are anxious to strike a balance between the entertainment, knowledge and pleasure children gain from highly profitable internet and computer games, as well as the dangers inherent in the unregulated world of the net and its overuse by children.

Under the Video Recordings Act, most games are exempt from the British Board of Film Classification and only lose this exemption if they depict, to any significant extent, gross violence against humans or animals. Other games can be classified by a separate, entirely voluntary pan-European scheme administered by the Video Standards Council.

Policing such regimes is difficult as it is possible to buy games over the net and simply tick the box stating the purchaser is over 18.

A new British Standards Institution specification proposed by Ofcom, the communications regulator, and the industry is expected to allow the developers of filtering products to test them against the standard designed to protect children and other users from illegal or unsuitable content. Companies that pass the test will be able to display a child safety online kitemark.

Ministers hope the Byron review will act as a way of calming the debate about video games which has become increasingly polarised and based on prejudice. They say they are also willing to examine proposals made by a Tory MP earlier this week for an internet standards authority to be set up to ensure that service providers offer a two-tier system with users able to pick content suitable for adults or children.

In a further sign of Tory concern, Julian Brazier will bring forward a private member's bill this month giving powers for a new body to appeal against decisions of the BBFC in its classification of video games and DVDs.

Hugo Swire, a former shadow culture secretary, has suggested that the default setting for internet content would be for children, with a password or pin needed for unfiltered material.