Animal activists are using a legal loophole to flout a ban on feeding pigeons in Trafalgar Square.
The square is patrolled by a Harris hawk who drives pigeons away
The Pigeon Action Group discovered the mayor of London's 2003 by-law only applied to land within the Greater London Authority's boundaries.
They have begun daily feeds from the north terrace - recently pedestrianised at a cost of £25m - which is under Westminster Council's control.
The council has asked for powers to ban feeding in its part of the square.
'20kg of mess'
Julia Fletcher, of Pigeon Action Group, said: "Members of our group are down feeding the pigeons on the square on a daily basis otherwise they would die."
Mayor Ken Livingstone, who once described the pigeons as "rats with wings" and a health hazard, has spearheaded the clear-out from the square.
Bird numbers have dropped from 4,500 to 700 since the feeding ban was introduced in November 2003.
A deal was struck with the Save the Trafalgar Square Pigeons group ensuring the birds got less food for breakfast before being driven from the area by a hawk.
Dr Leith Penny, Westminster Council's director of environment and leisure, said the council wanted a by-law that covered a wider area than just the square's north terrace.
"Sadly, encouraging large flocks of pigeons to gather by feeding them does produce a significant amount of mess and we have to clean that up," she said.
She said there have been occasions when people have been seen scattering 20kg (three stone) of feed at one time.