Migrating from Spain to UK

Hi,
This is for my uncle's family who is living in Spain. My uncle is an Indian citizen who has been living in Spain for past 15 years and he is permanent resident of Spain. His wife is also permanenet resident of Spain but citizen of India. Their daughter who is 6 years old is Spanish citizen who was born in Spain.

My question is do they qualify for UK permanenet residency?
which is the best way for them to start living in UK?

I appreciate your time reading my post and I hope to get best advice from you all.

Preferably they need to first upgrade their Spanish PR into Spanish citizenship then they can enter freely as EU national otherwise they need the visa to enter UK because Indians are visa nationals.

thanks for replying.
Once they get Spanish Citizenship, would they be allowed to live in UK permanently?

jss117 wrote:thanks for replying.
Once they get Spanish Citizenship, would they be allowed to live in UK permanently?

Yes.