Protestors say the council is "running scared" from them over their opposition to plans to build an incinerator in Beddington.
Campaigners from Stop the Incinerator were due to stage a protest at Sutton Council's St Nicholas Way base at a deveopment control committee meeting last Wednesday to mark the first anniversary of the committee's decision to grant planning permission to an energy recovery facility (ERF) in Beddington Lane.
How the incinerator will look by night
But the meeting was cancelled at the last minute leaving the campaigners to demonstrate in front of just a pair of police officers who attended the building.
The group said the cancellation is a sign that the council is running scared but a council spokesman said the meeting was postponed for an administrative reason.
Dave Pettner, of Stop the Incinerator, said: "The council are afraid of the truth.
"With one in twelve deaths in London being linked to air pollution the council’s position on this incinerator has become untenable.
"They can no longer defend the indefensible and are choosing to run and hide rather than answer the hard questions."
The council's committee granted planning permission for waste management firm Viridor to build the ERF last year.
It could be built as early as 2017 and will take up to 275,000 tonnes of non-recyclable rubbish from Sutton, Merton, Croydon and Kingston each year and burn it to create electricity and heat for nearby homes.
Campaigners fear the plant will pump harmful emissions into the environment but the council has said its research says it will be safe and has denied it is running from any discussion on the topic.
A spokesman said: "Sutton Council decided to cancel the Development Control Committee on May 7 due to the agenda being reduced to three items following the withdrawal from the agenda of the item concerning Sears Park, which was the only item that had attracted any objections."
The next development control committee meeting will happen on Wednesday, June 11.