Tamir was an ardent anti-Nazi leading proactive legal cases to prosecute perpetrators of the Holocaust and war criminals.

Tamir's maverick politics finally led him into an independent politician after several attempts of coalition with nationalist right-wing parties.

Katzenelson returned home with the last exiles from Kenya on 12 July 1948, after Israeli independence was declared; upon arriving in Israel, he adopted his code name, Tamir (meaning "tall and slender") as his legal name.

He had a notable career as a lawyer and conducted several famous political cases, including the Yedidya Segal and Rudolf Kastner trials.

As Dash disintegrated, Tamir joined the Democratic Movement, before leaving to sit as an independent MK (member of the Knesset).