Almost two-thirds of Egyptian voters approved an Islamist-backed constitution rejected by a secular leaning opposition which led protests in the run up to a referendum, according to unofficial preliminary results. State media reported 64 percent of voters opted for the new charter, which has Islamist overtones, over two rounds of voting that ended on Saturday. Official results are expected on Monday. The charter\'s adoption will be followed by parliamentary elections in two months, ending a tumultuous transition since an uprising overthrew president Hosni Mubarak in early 2011. Key points of the controversial draft constitution: - Islam remains Egypt\'s official religion. The previous formulation that the \"principles of sharia\" are the main source of legislation is maintained. However, these principles are broadened to include Sunni Muslim doctrinal interpretations. - \"Freedom of faith is guaranteed\" -- but only for Islam, Christianity and Judaism, not for other religions. - The president is limited to two consecutive four-year terms, not indefinitely as under Mubarak. - The constitution does not mention a vice president. Vice President Mahmud Mekki announced his resignation as voters were casting ballots Saturday. - The defence minister is chosen from within the military. Also, the military\'s budget will be decided by a committee dominated by military officers, effectively making it independent of civilian oversight. - Civilians will not be tried in military courts except in cases where the \"crimes are susceptible to harm the armed forces.\" The opposition and rights groups demand that this vaguely defined exception be removed. - The charter upholds \"the equality of citizens under the law without discrimination,\" but omits an explicit mention of equality of the sexes. - Freedom of expression is protected -- except when it comes to \"insults against physical persons\" or \"insults towards the prophets.\" Some fear those exceptions open the door to censorship. - The state is the designated protector of \"public morals and order.\" - It is forbidden for Egypt to sign international treaties and conventions that go against the constitution. Rights groups criticise the absence of an explicit reference to respect for international human rights conventions.