Ben Summerskill, the chief executive of gay rights group Stonewall said:
"Many people will be pleased by today's decision.
"Had these voodoo 'gay cure' adverts appeared in the pages of the Spectator or the Daily Telegraph it's unlikely there would have been complaints.
"But in a city where over half of gay young people face bullying at school, and where tens of thousands of gay people are subjected to hate crimes every year just because of the way they were born, it's perfectly proper for a mayor to object to the use of such advertising in an iconic public setting."
More top news
The Hollywood star took residents in Merton by surprise when he touched down in a helicopter near Poplar Road.
His shock decision to pull out of the Tory leadership contest came at the end of a speech where he appeared to set out his credentials.
The two newborn Sumatran tigers who are yet to open their eyes were born at London Zoo on Monday.