The government has been urged to include residual waste in official recycling rate statistics after Lambeth and Wandsworth councils were accused of exaggerating their figures by including waste sent for incineration.
Green Party London Assembly member Jenny Jones said the authorities had claimed a huge surge in recycling rates over the past year. Both reported an increase of nearly 20%.
But Jones said Defra figures, which only include household waste sent for reuse, recycling or composting, show the councils to be relatively poor performers. She argued that residual waste sent for incineration is not officially defined as recyclable material.
Speaking to the BBC, she said other London councils were not including incineration in their figures and that doing so amounted to “cheating” by “making it look as if they’re doing more than they really are”.
Jones called on London mayor Boris Johnson to instruct the authorities to “publish only official figures”.
In response, Pete Robbins, Lambeth cabinet member for neighbourhood services, said: “Current guidelines on recycling for local authorities in England make it difficult for the public to see the real picture.
“It’s time for the government to change its guidance so that all recycled materials are counted in national recycling figures.”
Wandsworth defended its inclusion of waste sent for incineration and pointed out waste was being diverted from landfill.
A spokesperson said: “We are extracting metals and aggregates for use in the construction industry from waste that cannot be recycled in any other way, and using residual waste to produce electricity for thousands of homes instead of using fossil fuels.
“Doing this prevents this waste from being sent to landfill, which the Greens have long advocated.
“All this information, including the data submitted to Defra, is clearly shown on our website in a wholly transparent and open way. We put it there so that members of the public can see exactly how our recycling figures are reached and can judge our performance for themselves.”