South Cambridgeshire District Council faces a fourth judicial review brought within three months from a local residents’ group.
The Fews Lane Consortium has now alleged that the council has acted unlawfully by misinterpreting its own climate change and water conservation policies.
Other judicial review cases have been launched in recent weeks.
It said the council had indicated to developers that future planning applications would be approved even if they did not include sufficient information to comply with these policies.
The latest challenge concerns a residential development in Longstanton, which the group said should be required under council policies to achieve a 10% reduction in carbon emissions above the minimum building regulations standards through on-site renewable energy or low carbon technologies.
But it said the council had instead agreed that burning off-site produced bioethanol fuel would satisfy this.
Transporting this fuel from where it is produced to the site would have a carbon cost and contribute to deforestation, the group said.
It also disputed whether water usage would be reduced in line with council policies.
South Cambridgeshire’s cabinet member for planning Tumi Hawkins, said: “Being ‘green to the core’ is one of our top four priorities in our business plan.
“As part of our latest budget we agreed to invest £5m to help tackle the climate emergency…we take our environmental responsibilities hugely seriously.
“With regards to this particular case, which relates to a new house on Fews Lane, Longstanton, we’ll continue talking to the applicant to try and resolve the matter as soon as possible.”