The UK parakeet population has grown at around 30% per year
People will be able to shoot parakeets from next year without a licence, a wildlife watchdog has ruled.
Around 44,000 parakeets are in the UK, with 90% living in London - but they can threaten smaller birds, crops and public safety, the watchdog says.
The move gives parakeets the same legal status as pigeons, crows and magpies.
A Natural England spokesman said: "They are still a protected species but there will be some circumstances where people can take measures to control them."
Originally from the Himalayas, the UK's population of red-beaked emerald green parakeets is growing at an estimated rate of 30% per year.
Theories as to how the exotic birds came to make their home here include the urban legend that they escaped from a container at Heathrow airport during filming of The African Queen in 1951.
Parakeets have increased in density around south-east England, especially Heathrow, Kew, Richmond, Middlesex and Surrey.
People wanting to kill the birds to control their numbers must currently apply for a "personal licence" from Natural England.
The new move applies a "general licence" to England which will enable land owners or occupiers to kill the birds from January 2010 - if they can demonstrate a legitimate reason for doing so.
"This doesn't mean that anyone can go into Richmond Park and just shoot or strangle a parakeet," said the Natural England spokesman.
"But if, for example, a council has a health and safety reason for controlling the number of parakeets in their area, and they have already tried other measures, this move enables them to do so."
Parakeets can be aggressive towards other birds, they can damage the environment and their droppings can create hygiene issues, he added.
Royal Society for the Protection of Birds conservation expert Grahame Madge said the ruling came as a "slight surprise".
"The inclusion of parakeets within the licence system does not alter the situation - it has not automatically become a pest," he said.
"This must not be seen as a free-for-all cull or a widespread charter for removing the birds."