"It is for the Court to determine in the last resort whether the requirements of Article 3 of Protocol No. 1 have been complied with; it has to satisfy itself that the conditions do not curtail the rights in question to such an extent as to impair their very essence and deprive them of their effectiveness; that they are imposed in pursuit of a legitimate aim; and that the means employed are not disproportionate (see Mathieu-Mohin and Clerfayt, cited above, § 52). In particular, any conditions imposed must not thwart the free expression of the people in the choice of the legislature – in other words, they must reflect, or not run counter to, the concern to maintain the integrity and effectiveness of an electoral procedure aimed at identifying the will of the people through universal suffrage. Any departure from the principle of universal suffrage risks undermining the democratic validity of the legislature thus elected and the laws it promulgates. Exclusion of any groups or categories of the general population must accordingly be reconcilable with the underlying purposes of Article 3 of Protocol No. 1 (see Hirst (no. 2) [GC], cited above, § 62, and Scoppola (No. 3) [GC], cited above, § 84). "