[JURIST] The Turkish Constitutional Court [official website] ruled Tuesday that the first parliamentary vote on the only candidate standing for election to the presidency of Turkey was invalid because a quorum of legislators did not participate in the vote as required by the Turkish constitution [text]. Under Article 102 of the constitution, two-thirds of a total of 550 legislators are required to vote in order to establish a quorum for the first round of presidential balloting [JURIST report]; although as many as 368 lawmakers may have been present [Turkish Daily News report] at the outset of proceedings, only 357 legislators actually cast ballots last Friday, 10 short of the required quorum. The opposition Republican People's Party (CHP) [Wikipedia backgrounder] boycotted the vote over concerns that candidate Abdullah Gul [official website; BBC profile], currently Turkey's foreign minister and a member of the ruling Islamist-rooted Justice and Development Party (AKP) [party website, in Turkish; Wikipedia backgrounder], would not be entirely secular. The secularist Turkish Army [official website] has also threatened to intervene if Gul is elected [Times report].

After Tuesday's ruling was announced, the government said it would consider holding early general elections. Justice Minister Cemil Cicek also said that the AKP would seek constitutional amendments to lower the minimum age for candidates before agreeing to hold new elections. Meanwhile, protesters calling for the resignation of the prime minister clashed with police [AP report] in Istanbul. Some 580 protesters were detained. Faced with mass protests over the weekend, Gul insisted that he would not withdraw from the election [JURIST report]. AP has more. BBC News has additional coverage.