Parents have resorted to "threats and other aggressive tactics" in their attempt to block a Jewish school's proposed change to its admissions procedure, it has been claimed.
Yavneh College, in Borehamwood, wants to end its feeder school system, a plan which has sparked fierce opposition from families who say their children will be denied places.
A Yavneh spokesman said parents had threatened legal action and had warned that they would report the school to statutory bodies.
Aggressive language had been used in correspondence, with some people questioning governors' professional integrity, even suggesting they were criminals, according to the spokesman.
"It seems that a minority of parents will stop at nothing to place the interests of their own children over other families," he said.
The result of a consultation carried out by the school is due at the end of the month. Yavneh said pressure from parents would have "no bearing on the final decision".
The comments came as a group of parents said they had complained to the Department of Education, accusing Yavneh of failing to adhere to the government's school admissions code and its funding agreement. The DfE said it was investigating.
The group - which represents more than 400 parents of children at the feeder schools likely to be dropped under the proposals - also complained to the Information Commissioner's Office, over data released by the school under a Freedom of Information Request.
The group claimed the school failed to provide the data it asked for.
Yavneh released two sets of figures last month, showing the likely effect of the plan on admissions.
The parents' claimed the numbers were misleading and did not include specific cases of children who would have lost their places under the plan.
The school said the parents' interpretation was based on a misunderstanding of the figures.
The group's spokesperson said: "We told the school we know the table is wrong. We knew the names of pupils who came from areas that were not mentioned in the figures. We asked the school to confirm these cases and they refused.
"They make their decision based on impact analysis. Their impact analysis is clearly wrong and they just don't care."
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