Twenty years after Pope PAul VI issued his encyclical on the progress of peoples, his second successor issued another document in the same vein. Cited in paragraph #400:
400. Hence, from our condition as disciples and missionaries, we want to energize the Gospel of life and solidarity in our pastoral plans in the light of the Church’s social doctrine. We also intend to promote more effective ecclesial ways of taking action in social matters with the preparation and commitment of laypeople. John Paul II offers reason for hope:
However imperfect and temporary are all the things that can and ought to be done through the combined efforts of everyone and through divine grace, at a given moment of history, in order to make people’s lives more human, nothing will be lost or will have been in vain. (Sollicitudo Rei Socialis 48)
So, don’t quote something about the poor always being with us. That’s a reflection on human sinfulness. Not a commandment.
For deeper examination, an English translation of the 2007 document from the Aparecida Conference.