The UK has been trying to deny EU citizens who naturalise as British, any rights under EU law, which would be a problem for any dual national who wishes to sponsor family members or who has a non-EEA spouse, however, in the Lounes case, the European Court of Justice ruled that EU citizens who move to the UK and later naturalise as British retain their free movement rights under EU law even after becoming British.

Press Release about the Lounes Judgment
Toufik Lounes v Secretary of State for the Home Department

The Lounes judgment has now been implemented into law in The Immigration (European Economic Area) (Amendment) Regulations 2018 that came into force 24th July 2018.

Press release PDF: cp170121en.pdf
Attached Files