"But the definition of what is a replica firearm is a question that needs careful consideration.
Home Office minister Charles Clarke revealed that such a move was possible when he spoke at an exhibition of seized fake weapons, which included imitation Uzi machine pistols and an SA-80 assault rifle.
The minister said replicas posed a "real threat" to society.
Theatre use
But he warned the laws would have to be carefully drafted to avoid legitimate uses of imitation weapons such as in theatres and for films.
"Our aim is to get to a position where replica firearms are banned," said Mr Clarke.
"But the definition of what is a replica firearm is a question that
needs careful consideration.
"Would toys of a much smaller size than the real thing fall under such a ban, and what about the kind of imitation that is used on stage?"
A Home Office spokeswoman later stressed the ban would include realistic toy guns, but not small, plastic ones intended for children.
The exhibition comes in the week that 15-year-old American student Andy Williams opened fire at his San Diego high school, killing two children and wounding 13.
Gun fashion
Commander Mike Fuller, head of the Metropolitan Police anti-firearms Operation Trident, said more young people were openly carrying realistic fake weapons as fashion accessories.
"It's a very unhealthy fashion but there is a cultural aspect to it within a
section of black youths who follow `gangster rap' and that type of music," he said.
Commander Fuller added that the Met would support a ban on replica firearms in public places.
Gill Marshall-Andrews, chairwoman of the Gun Control Network which organised the display at the Houses of Parliament, said: "The situation is getting worse by the day and the proliferation of these weapons is very alarming."
Latest statistics show the use of handguns in crime reached its highest level for seven years in 1999-2000, when 42 people were killed with weapons, which were involved in nearly 3,700 crimes.
Gun sports enthusiasts maintain the figures prove the problem never lay with licence owners and the ban has failed to have an effect on illegally-held firearms, particularly those in the criminal underworld.
The Home Office's firearms consultative committee is currently examining the legal options for a ban.
About 30 different weapons from the Metropolitan Police archives were on show at Wednesday's exhibition.