You must keep parents informed
Where it is decided that a pupil does have special educational needs (SEN), the pupil's parents must be formally informed that special educational provision is being made.
That's set out in paragraph 6.43 of the statutory SEND Code of Practice.
Hold meetings with concerned parents
If parents or carers don't want to accept that their child has SEN, organise a meeting to discuss how you can best support the child's learning.
If the parents have a good relationship with the pupil’s class teacher or teaching assistant, invite them to the meeting to share their observations.
Bring examples to the meeting that demonstrate the gaps in the pupil's learning, or lack of progress. Organise the evidence chronologically to show progression.