The United Kingdom is part of the European Economic Area (EEA) and therefore permits free movement between nationals of its Member States. An EEA national who resides in the UK , or who intends to reside in the UK , and is economically active can sponsor a dependent Child, Fiancé(e), Grandchild, Great Grandchild, Grandparent, Great Grandparent, Parent or Unmarried partner.
Non-EEA nationals whose family member is exercising their Treaty Rights in the UK may be eligible for maximum period of five (5) year residence family permit. This allows the applicant to live, work and study in the UK without restriction.
Ultimately, the applicant may be able to apply for Indefinite Leave to Remain (ILR) and British Nationality.