Their budget will be slashed to £56 million next year before disappearing altogether in 2012.
Hundreds of jobs will be lost in the process.
However, the huge funding reductions means that many of the Mayor's development and environment programmes will soon cease to exist entirely.
"The Government has cut the Mayor's plans to create 14,000 jobs, cut our energy bills and revitalise our parks. With no money to pay for his flagship programmes, his climate change strategies now lie in tatters. The Mayor's defence of the environment was more of a Maginot Line than a Stalingrad moment."
“The Mayor’s so-called ‘Stalingrad-like’ defence of London is a sham. Events this week suggest an approach reminiscent of Dads Army than the Stalingrad style defence Boris Johnson promised."