This instruction to French ambassadors came from Alphonse de Lamartine, a French poet who at the time served as France’s Minister of Foreign Affairs. For Lamartine, Polish independence was an essential cause, part of the common French-Polish interests.
Lamartine's approach stood in a rather sharp contrast with the political idea most famously embraced in another quote expressed in the French language: Il faut se débarrasser de la Pologne ('One should get rid of Poland') – the motto was particularly popular in the circles of Russian liberal Slavophile elites.
All in all, France had traditionally much sympathy for the Polish insurrections (1830, 1846, 1848, 1863). During the 19th century, many French poets expressed their solidarity with the Polish national cause, including Alfred de Musset, Pierre-Jean de Beranger, Alfred de Vigny, Victor Hugo, and Casimir Delavigne. The latter was the author of La Varsovienne, written during the November Uprising.
Alexander Herzen: Poland as a bridge (1851)