Sidqi was one of at least four Palestinian Arabs, the other three being Mahmoud al-Atrash, Ali Abds al-Khaliq and Fawsi al-Nabulsi, who are known to have fought on the Republican side in the Spanish Civil war. This kind of involvement was harshly criticised by mainstream Palestinian newspapers (although not by local Communist pamphlets). Reflecting the general trend of the Palestinian national movement, newspapers like Filastin were averse to Communism and backed the Spanish Fascists, partly out of a desire to antagonise both Great Britain and France, the region's colonial powers.[21] While in Spain, where he arrived in August 1936,[22] Sidqi undertook, on Comintern instructions, to travel under a Moroccan alias, as Mustafa Ibn Jala, and conduct propaganda aimed at dissuading Moroccans in Franco's forces from fighting on the fascist side.