son left out of will

[babyblues131]

my dad wrote a will 2006...my son born 2007, my dad died 2008.. he didnt update his will, so all his 4 grandchildren are inheriting 50,000 each including 4 properties which are to be sold and monies go them also.. My son isnt on the will because it wasnt updated, even though my dad told me he was investing money for all the grandchildren. My brother reassured me after our dads death that my son (his nephew) would be added onto the will - a deed of variation, so he would get the same share which my dad wanted. However, after 6 months and many solicitor visits, waiting to change the will, I am told by my debt ridden brother, who has broken down in tears about his debts, that legally he doesnt have to put my son onto the will, and he needs the money more because of his problems..and a baby doesnt need it and he does,,,his needs come first.. Myself and my wife are distraught, very upset that this is NOT what my dad would have wanted, and our son wont have a fantastic financial start when he is older like the rest of the children. I have read about pretermitted heirs where a child is left out of a will unintentionally, ie born after the will is written, and apparently my son should have the same share as if there was no will. but my solicitor says no...can anyone help please..its very upsetting for me and my family. thank you,