[24][25][26] Idealistic and pragmatic at the same time, in Thessaloniki Benaroya played a leading role in the creation, in 1909, of the mainly Jewish Socialist Workers' Federation, or in Ladino, Federacion.

It created combative trade unions, attracted important intellectuals and gained a solid base of support among Macedonian workers while cultivating strong links with the Second International.

Both monarchist and Venizelist policy actually assisted the emancipation and the radicalization of the left, and Benaroya, keeping equal distance from both established political groups, was quick to turn the situation to advantage.

In the 1915 general elections Federacion sent two deputies representing Thessaloniki (Aristotelis Sideris and Alberto Couriel) to the Greek Parliament, while it lost by only a few votes for a third seat.

Modern states should be based on free association and allow self-definition and self-organization of ethnicities in cultural affairs, while a mixed parliament, proportionally representing all nations of the realm, should decide on economic and political questions.

The Federacion traced the origins of its federative position in Balkan authors of the Enlightenment like Rigas Velestinlis, and stressed that the forthcoming peace should exclude any change of borders or transfer of populations.

Benaroya was always very interested in combating anti-Semitism, while over later years he shifted his emphasis to reflect the sizable Thessaloniki Jewish community that chose to remain within the Greek state.

Subsequently, social and political polarization, as well as the prestige of the newborn Soviet Union, strengthened the radicals and before long the party was affiliated to the Leninist Third International.

The Labour Centre of Salonica, another creation of Benaroya's, which united more than twelve thousand workers of all nationalities, a good part of them Jews, became the focus of radical socialism.

A little later, in December 1923, Benaroya, together with Couriel and Kordatos, who preferred social-democratic organizational models and opposed radical Bolshevisation considering the circumstances not suitable for a revolution, were expelled from the Communist Party of Greece and he was obliged to quit the editorship of Avanti.

In Thessaloniki he had a difficult political life, especially after the Liberals' more nationalist turn by the end of the decade, and the repeated coups d'état of 1935 that destroyed the Republic and the hopes of the democratic left.

In the 1940s he lost a son during the Greco-Italian war, he survived the Nazi concentration camps, and led a small socialist party in Greece after his return collaborating himself with Alexandros Svolos.