Name of bbc1 film about a gambler-splits-partner, little boy stays-grandad plants flower you are my sunshine?

My mum watched this film on BBC 1 a couple of months ago about a gambler who splits from his partner after stealing holiday money, their son goes to live with the grandad until the father sorts himself out, they do alot of gardening, mum and dad eventually marry I think the grandad dies but plants flowers in the garden saying you are my sunshine, my mum thinks its called this but I can't find any films with this name can anyone help?

Name of bbc1 film about a gambler-splits-partner, little boy stays-grandad plants flower you are my sunshine?
Sunshine steve coogan benard Hill
Reply:Sunshine.
Reply:Sunshine, but it was a show with 3 parts, not a film.
Reply:Im sure it was called Sunshine