A six-week consultation on the plan began last week after an inspector said a reference to a separation belt duplicates green belt policy.
He insisted that the plan, which aims to help deliver 12,000 homes east of Cambridge, will be declared unsound unless the citation is removed.
But council policy manager Keith Miles maintained: "Green separation policy brings in other proposals for landscaping. It screens views of Cambridge from villages and makes a narrow gap more effective."
The planning framework for an urban extension at Trumpington West was approved by the Planning Inspectorate last week. The decision, which could see 1,200 homes and a country park developed, means that the scheme can be formally adopted in January.
However, a further site earmarked for 1,000 homes may need to be allocated. This is because of a potential housing shortfall in documents such as the core strategy, three area action plans and a site-specific allocation plan, Miles said.
"The inspector thinks that the documents will collectively deliver 19,000 homes, but we believe that it is nearly 20,000," he added.
"The North West Cambridge area action plan covers any shortfall and is only six months off submission to government. But the inspector will not take that into account," he complained.