My father was refused a visa to visit my brother and his new born grand childnewborn son, my father's grandchild, based on not having enough ties back at histo this country of citizenship ( IranIran). He He would like to contest this as he has travelled to the USA and to many European countries many times years ago and he never overstayed his tourist / visitvisit visa.
Is there some sort of human rights law that we can mention in the appeal letter to request himon the basis of not being deprived from seeing his son and nowhis new grandchild?