Can I ask to keep my DS (7) back a year?

[Lorelei2]

My DS (7) is struggling in class and I wonder if he's too young.
We did ask whether he could be deferred when he started school but they said no, he'd have to have been psychologically assessed and a good reason given. And, as far as they were concerned they felt he'd be fine.
However my DH and I both knew that he was immature and difficult to manage, the nursery teachers had already complained to us that he doesn't listen at all.
So when we had to send him to school we were worried he'd feel anxious if he couldn't do something and it was perhaps because he should've been in the year below.
We still worry about this and wish we'd maybe tried harder to have him deferred.
Has anyone else had this issue with a child who they believe should have been deferred and are still worried that they are not coping as well as they should?

A friend has DTwins who were born end of Aug and at 34 weeks. She successfully deferred entry to Reception for 1 year. They started Reception out of year and will remain in that year group, not having to miss a year later on. The rationale was that they were prem, had they been full term they would have been born in the following years age catchment.

They started Reception a week or so after their 5th birthday and have flourished. There was no SEN or missed milestones, just age appropriate levels of maturity and readiness. Absolutely the right decision.