In 1922 Torp was a delegate at the Fourth Comintern Congress. In 1923 the revolutionary wing that had assumed power in the Labour Party in 1918 had split into two wings, one for and one against Comintern membership. Torp belonged to the latter wing, which assumed power at the 1923 national convention. Torp was elected chairman of the entire party. When he became chairman, the chairman of the party's youth wing (Peder Furubotn) was four years older than he was. Torp chaired the party until 1945. It has often been said, however, that Martin Tranmæl was the "real" chairman of the Labour Party.