Meijers Committee standing committee of experts on international immigration, refugee and criminal law - third, as regards the proportionality of the differential treatment, several states (Austria, Germany, the Netherlands and the UK) allow deprivation of citizenship without a prior criminal conviction. In most cases, the impact of citizenship deprivation on the individual concerned will be very severe. The person is deprived of a central element of his or her identity, of the right to return to that state and to live and work there among family and friends and loses all political rights in and the protection by that state. If dual nationals can be deprived of their citizenship without a prior criminal conviction this will further enhance the insecurity of their citizenship compared to that of single nationals; - fourth, the difference in treatment between dual and single nationals is especially difficult to justify with regard to dual nationals who are unable to renounce their second nationality. For persons in this situation, citizenship deprivation amounts to a sanction that can be imposed on them because of an element of their identity acquired at birth which they are unable to control.127 Yet the practice in the Netherlands shows that it is precisely the immutability of this characteristic that has allowed the Dutch authorities to identify dual nationals and propose withdrawal of their Dutch nationality (see paragraph 7, Indirect differential treatment on the ground of racial or ethnic origin); - fifth, deprivation of citizenship will be more difficult to justify where more time has passed since the acquisition of citizenship. It is noteworthy that both the French Conseil Constitutionnel and the German Bundesverfassungsgericht considered that the possibility of citizenship deprivation should be limited in time to a certain period after the acquisition of citizenship.128 Otherwise the effect will be that the citizenship of dual nationals, many of whom belong to ethnic minority groups, will always remain conditional. This applies all the more to those who acquired the citizenship by birth. The passage of time since the acquisition of citizenship also forms part of the proportionality analyses conducted by the CJEU and the ECtHR in cases on citizenship deprivation.129 8. Conclusions This policy brief signals that measures aimed specifically at dual nationals constitute a threat to the ideal of equal citizenship, in particular for citizens of immigrant origin. This is especially visible in the area of nationality law: in eight EU Member States and in the United Kingdom dual nationals are at risk of being deprived of their citizenship in relation to (alleged) terrorist activities, a threat that is not felt by single nationals. The practice in these Member States confirms that most persons who are deprived of their citizenship on this ground are members of racial or ethnic minorities. Moreover, the discriminatory effects of citizenship deprivation of dual nationals have been subject to debate in both France and Germany. In addition to political objections, differential treatment of dual nationals is questionable from a legal perspective. Because dual nationality serves as a proxy for immigrant origin, differential treatment of dual nationals amounts, in principle, to indirect differential treatment on the 127 Cp. the ECtHR in Bah/United Kingdom, para 47 and the CJEU in Tjebbes, para 46. See paras 5 and 7.2. 129 Rottmann, para 56; Ghoumid and others/France, para 50. 128 26