Thousands of signatures on a petition opposing a £1.4bn incinerator in North Yorkshire have been handed into Downing Street.
Protesters say the plant at Allerton Quarry, near Knaresborough, would be an eyesore and more money should instead be spent on recycling.
The government is to provide £65m under the private finance initiative.
North Yorkshire County Council has said the plant will save 90% of waste from going to landfill.
Campaigners have set up the North Yorkshire Waste Action Group to fight the plans.
Some representatives travelled to London earlier to hand over the petition containing more than 9,000 signatures.
The county council will meet next month to decide whether to award the contract to the preferred bidder AmeyCespa.