Complex sentence: On 18 September 2009 the remaining three members left the party to create a new party, Hreyfingin ("The Movement"), and so the Citizens' Movement is no longer represented in the Althingi.
Split into simpler sentences: On 18 September 2009 the remaining three members left the party to create a new party, Hreyfingin ("The Movement"). Henceforth, the Citizens' Movement is no longer represented in the Althingi.