Szmul Zygielbojm - Porchester Road, London, UK - Blue Plaques on Waymarking.com

The full wording on the green plaque reads:

City of Westminster

Jewish Workers' Bund Leader
Representative to the
Polish Parliament-in-exile
Szmul "Artur"
Zygielbojm
1895 - 1943
Took his life in protest
at the world's indifference
to Nazi extermination
of the Jews
Lived nearby
1942 - 1943

Wikipedia has an article about Szmul Zygielbojm that advises:

Szmul Zygielbojm (February 21, 1895 – May 11, 1943) was a Jewish-Polish socialist politician, leader of the Bund, and a member of the National Council of the Polish government in exile. He committed suicide to protest the indifference of the Allied governments in the face of the Holocaust.

In May 1996, a plaque in memory of Zygielbojm was dedicated on the corner of Porchester Road and Porchester Square in London, near Zygielbojm's home. The creation of the memorial had been a joint project of the Bund and the Jewish Socialists' Group. Among those who participated in the memorial's unveiling were members of Zygielbojm's family, the Polish ambassador, and the mayor of Westminster. Every May, supporters of the Szmul Zygielbojm Memorial Committee gather at the memorial.