What sources are there if you find a childs not developing in line with expectations who world you contact and what world you do. I doing the paperwork and I'm stuck so i thought I asked you good people :)

DeVelopment worker, senco, health visitor, speech therapist, portage.
All with parental permission although you could talk to them in a hyperthetical situation for some guidance and not breech confidentiality before approaching parents to make sure you are on the right lines.

You cannot contact anyone without parents permission - so the answer is to inform parents and keep careful records.

Even with the 2 year check if parents choose not to give it to HV because they don't agree with the contents there is nothing you can do.

it's beyond a joke when you know there's a problem and parents are in denial but your hands are tied :(