Acquisition of a right of permanent residence is a prerequisite to qualify for enhanced protection against expulsion
The period of ‘ten years’ for which a citizen must, if he is to be protected against expulsion, have resided in a Member State other than his own may include periods of absence or of imprisonment provided that one of those periods has not had the effect of breaking integrative links with that Member State
Under the directive on free movement and residence.’ EU citizens who have resided in a Member State other than their own (the host Member State) for a continuous period of five years are to acquire a right of permanent residence in that State. In that context, the host Member State may not take an expulsion decision against an EU citizen who has acquired a right of permanent residence on its territory, except on serious grounds of public policy or public security.
Similarly, an expulsion decision may not be taken against an EU citizen who has resided in the host Member State for ‘the previous ten years’, unless the decision is based on imperative grounds of public security, as defined by that State.
Read more: European Court of Justice, http://bit.ly/2AbTHBe