It was formed as a split from the Socialist Workers Party in 2013 following the alleged rape scandal concerning former National Secretary, Martin Smith.
[1][2] According to the group's Autumn 2014 Discussion Bulletin, it was "a tendency within Left Unity".
[3] The ISN also participated in unity talks involving other organisations, some of which are involved in Left Unity, including Workers Power, Socialist Resistance, Anti-Capitalist Initiative and Revolutionary Socialism in the 21st Century (RS21).
It published regular 'internal' bulletins that are also publicly available, and one issue of a proposed journal, 'Cactus'.
[4] The ISN voted to disband at a national meeting in May 2015 and encouraged members to join other socialist organisations.