Cannabis plants, some as large as three foot high, have been found growing alongside the Tower of London and along the South Bank .
#Feed420 activists have been scattering hemp seeds across the capital to provoke the government into changing cannabis laws for those using it for medicinal purposes.
The group allege what the are doing is legal as they are simply “feeding the birds.” The Home Office has confirmed the group were not breaking the law, as long as they were not cultivating the plants.
Spokesman, Finn Hemmingway said: "The oldest are three months old and were planted eight to 10 weeks ago.
"I think a fair amount of them have gone unnoticed, in the coming months they will become more obvious.
"The war on drugs is a catastrophic failure, and I think that cannabis growing openly on the streets of London emphasises how ludicrous our drug laws are. Putting a human in a prison cell for using a plant is the crime."