In a letter to the Governor of Tehran province, eight reformist parties have made a formal request to hold rallies on the first anniversary of last June’s presidential election. According to the reformist Parleman website, the joint request comes just days after Green Movement leaders Mir-Hossein Mousavi and Mehdi Karroubi also signed a joint letter requesting authorisation to hold a demonstration on 12 June.
In the letter, the reformist groups and factions including the Islamic Iran Participation Front (Mosharekat) and the Mujahedin of the Islamic Revolution Organisation have referred to article 27 of the constitution of the Islamic Republic which guarantees the right of assembly, provided arms are not used and the assemblies are not detrimental to Islamic principles.

source: The Green Voice of Freedom