Council chiefs have accused government inspectors of "gambling" the future of a plan for 50,000 homes on three sites for gypsies and travellers.
John Fuller, the leader of South Norfolk Council (SNC), condemned a proposed consultation for the new pitches as being "clearly unreasonable".
Three sites were identified for further consultation, in Cawston, Costessey and Wymondham.
They were put forward as part of the Greater Norwich Local Plan (GNLP), which covers housebuilding in the city, Broadland and South Norfolk over the next two decades.
Government inspectors have said the GNLP must include pitches for the traveller community, without which the entire plan would be rejected.
Speaking to his SNC cabinet colleagues on Monday, Mr Fuller said: “The inspectors have been labouring, quite unreasonably, with the suggestion that unless we find these 20 spaces, and I will say that 18 of the 20 are in south Norfolk, then the entirety of the local plan must fail.
“That is clearly unreasonable - [legally] unreasonable - and must be challenged.”
Mr Fuller, accused the inspectors of "overreaching" themselves, leaving the authority with no alternative but to approve the sites and "gambling" the entire plan.
He also objected to the inspector's suggestion that consultation responses be sent directly to them rather than go through SNC.
The Costessey site was highlighted as a particular concern.
Located off Bawburgh Lane, it has space for 18 pitches and would only be delivered if an 800-home development on the site was delivered.
Mr Fuller said the consultation did not make clear where they would be on the site and the Costessey scheme was a 'contingency' site and may not go ahead.
SNC's cabinet members stressed they were not against having sites for travellers in the district but said the government inspectors had turned the consultation into a "sham".
Mr Fuller said: “No other authority in England has a better record than us over the last 20 years of proactively finding sites.
"We take our responsibility to the gypsy and traveller community very seriously.”
Liberal Democrat Costessey councillor Terry Laidlaw agreed with Mr Fuller, saying the sites had "come out of the blue" and could disrupt talks the parish council is having for a new community centre in the area.
Mr Fuller said the travellers' sites need to be detached from the rest of the plan.
While Norwich City Council's cabinet approved the consultation last week all three GNLP authorities must unanimously approve the decision.
The consultation will now be reconsidered.
The three sites
The Cawston site would be on land off Buxton Road, Eastgate, with space for around four pitches. It is the only privately-owned space that has come forward in the GNLP, with all other areas being on council land.
The Costessey site, on land off Bawburgh Lane, north of New Road, has space for 18 pitches. The plans would be added to an 800-home development on the 153-acre site, which is part-owned by Norwich City Council.
The final site could be at the current Wymondham Recycling centre, on Strayground Lane, which has space for two pitches. This site is owned by Norfolk County Council, which announced it plans to move from the site to a new location.
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