24 SITAROPOULOS AND GIAKOUMOPOULOS v. GREECE JUDGMENT set up abroad, and/or postal voting, proxy voting and e-voting (see paragraph 34 above). The length of residence abroad is another factor taken into consideration by member States. Some grant voting rights only to nationals temporarily resident outside the country, while in others expatriates lose the right to vote after a certain period of time (see paragraph 35 above). Furthermore, some Contracting States make provision for expatriates to elect their own representatives to the national parliament, in electoral constituencies set up outside the country (see paragraph 37 above). Lastly, in the majority of member States which allow voting from abroad, persons wishing to avail themselves of this facility must register by a certain deadline on the electoral roll with the authorities in their country of origin or the diplomatic or consular authorities abroad (see paragraphs 39-45 above). 75. In short, none of the legal instruments examined above forms a basis for concluding that, as the law currently stands, States are under an obligation to enable citizens living abroad to exercise the right to vote. As to the arrangements for exercising that right put in place by those Council of Europe member States that allow voting from abroad, there is currently a wide variety of approaches. 76. Secondly, with regard to the domestic legislation in issue in the present case, the Court observes that Article 51 § 4 of the Constitution provides that “[t]he conditions governing the exercise of the right to vote by persons outside the country may be specified by statute ...”. The Scientific Council of Parliament, for its part, stated, in its report of 31 March 2009 on the bill concerning the exercise of the right to vote in parliamentary elections by Greek voters living abroad, that permitting the exercise of the right to vote from abroad was an option rather than a duty for the legislature, while stressing that legal opinion was not unanimous on the subject (see paragraph 19 above). In conclusion, it would appear that while Article 51 § 4 of the Constitution allows the legislature to give effect to the exercise of voting rights for expatriate Greeks from their place of residence, it does not oblige it to do so. Accordingly, and having regard to the considerations outlined above (see paragraph 75), the Court is of the view that it is not its task to indicate to the national authorities at what time and in what manner they should give effect to Article 51 § 4 of the Constitution. 77. Furthermore, since 2000, the Greek authorities have made several attempts to give effect to the provisions of Article 51 § 4. During the 2001 constitutional revision, for instance, the content of these provisions was clarified and it was stated that the principle of simultaneous voting did not rule out the exercise of voting rights by postal vote or other appropriate means, provided that the counting of votes and the announcement of the results were carried out at the same time as within the country (see paragraph 16 above).