Bournemouth Christchurch Poole Council has suspended planning consent for almost 700 homes after a local environmental group said it had acted unlawfully.
The council had approved an application by local developer WH White to build at Canford Park. But the Bearwood Action Group said it instructed planning solicitors Richard Buxton to examine what had happened.
The firm concluded the council had acted unlawfully in deciding that a foul water pumping station comprised appropriate development on the green belt, and for ignoring concerns raised by its senior rights of way officer about building a road across the Stour Valley Way footpath.
A council spokesperson said: “The planning application for new homes in Bearwood will be going back for consideration by planning committee.
“It has become apparent that there are a couple of areas of the assessment which officers felt planning committee members needed further clarification on in the interests of openness and transparency in the decision making process.
“This relates to the location of a small water pumping structure, which would serve the housing development.”