The Labour government has awarded Gloucestershire County Council £92m of PFI credits for its residual waste project.
The business plan put forward by the county's Conservative cabinet is for a massive waste incinerator at Javelin Park, to the south of the city.
Gloucestershire County Council has recently purchased the site after months of negotiation.
The waste incinerator will burn up to 175,000 tonnes a year for a period of 30 years.
On the 17th of February, the county council held an industry day to brief potential operators of the incinerator. Outline solutions have to be in by 26th June.
Currently the county recycles 43% of its waste and has a target of 60% recycling. Liberal Democrats are urging the county to set an ambitious target to recycle 70% of household waste.
Jeremy Hilton said: "Liberal Democrats are demanding that other technologies are considered for the residual waste facility.
"The massive incinerator that the Tories propose will only encourage the burning of recyclable waste and waste from out of county - just to maintain the beast's appetite.
"Toxic ash from the waste incinerator will be dumped in Gloucestershire at Wingmoor Farm landfill site.
"We must aim to reduce, reuse and recycle more of our waste than we do currently.
"There are other more environmentally friendly methods for processing residual waste such as Mechanical Biological Treatment.
"Liberal Democrats will halt the Tory project to build a massive waste incinerator at Javelin Park, if we take power on 4th June."
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