Inspector’s Laura Graham and Alan Wood wrote to Cambridge City Council and South Cambridgeshire District Council over the publication of correspondence regarding the inspection of the Cambridge and South Cambridgeshire local plans.
The two councils last week made emails between the inspectors and the councils public, and in a joint press release, said that the inspectors "did not raise any objections to the strategy of focusing growth in new towns and a new village".
But the inspectors subsequently wrote to the councils expressing "surprise" that they were not informed about the publication of emails.
"Bearing in mind that this could lead to a significant level of correspondence from representors and others, we would have expected you to contact the programme officer in advance, not only as a matter of courtesy, but also in the light of the requests we have made that no new reference documents should be added to the already extensive reference documents list without our prior agreement," the letter said.
The inspectors added that the suggestion in one email which claimed that they had not raised "fundamental concerns" with the development strategy was inappropriate.
"You will recall that we raised some fundamental concerns regarding the development strategy in our preliminary conclusions of May 2015," said the letter.
"The council undertook further work to address these concerns and the examination has continued. However, our final conclusions will be contained in our reports to the councils and it is not appropriate for you to jump to conclusions prior to the receipt of our reports."
A South Cambridgeshire District Council spokesman said: "Our intention was to update people on the stage the local plan had reached and we have apologised to the inspector for any confusion."
Cambridge Council has also been asked to comment.