Szmul Zygielbojm, a leading member of the Jewish Bund, killed himself in London on 12 May 1943 by taking poison. Zygielbojm arrived in London from the USA in March 1942, to represent the Bund on the Polish National Council- a quasi-Parliament in exile. He substituted for Henryk Erlich - the original choice - who had been arrested in Russia. In pre-war Poland, Zygielbojm had been active in the Bund Central Committee, in trade unions and in local politics, and was a 'seasoned politician'. In the third week of May 1942, Zygielbojm received a key report from Leon Feiner, a member of the underground Bund in Poland, which revealed the 'physical extermination of the Jews on Polish soil'. The Labour Party resolution of 15 December had marked an important turning point in Zygielbojm's influence, as his first success was then to recede.