5. Any dwelling occupied in whole or in part as his only or main residence—
(a)by a partner, close relative, grandparent, grandchild, uncle, aunt, nephew or niece of a relevant person who is single or of any member of the family of the relevant person where that person is either aged 60 or over or incapacitated;
(b)by the former partner of the relevant person; but this provision shall not apply where the former partner is a person from whom the relevant person is estranged or divorced.