A cluster of schools has warned its parents they could face legal action if they continue to use the staff car park to drop off children without permission.
The headteachers of Kinsale junior and infant schools in Hellesdon, along with the manager of Hellesdon Pre School, have written to parents citing concerns over the site being used for school runs.
The three schools, which share a site off Middleton's Lane, do not allow parents to use the site for dropping off children unless they have specific permits - instead requiring them to use nearby streets.
However, some have continued to drive up to the school gates and drop their children off in the car park.
The letter includes allegations that parents without permits had reacted angrily to being questioned.
It reads: "We have even had a minority of parents be extremely rude and defensive when being asked to see their pass - which is completely unacceptable."
It has sparked warnings that this could be deemed as "trespassing" and that the schools will "seek legal advice" after monitoring continued use via CCTV.
Roz Robinson, headteacher of Kinsale Junior, said: "The letter was sent to parents following numerous concerns about the potential dangers created by the number of vehicles entering and exiting the site during drop-off and pick-up times.
"Parents are carers are aware that vehicles should not be on the school site unless there is a specific need and no alternatives.
"For those with specific needs we have issued permits and asked for these to be on display."
Ms Robinson added that the latest letter came after previous warnings saw parents continue to ignore the rules.
She added: "Our priority is to ensure the safety of the children coming onto the school site and we hope the school community supports us on this."
However, parents have told BBC Radio Norfolk they have little alternative or safe places to stop nearby.
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