If there was an event that demonstrated the fascist menace before the destruction of Czechoslovakia in March 1939, it was the Spanish Civil War. The conflict roused the passions of an entire generation of left-wing intellectuals, many of whom fought in the conflict on the Loyalist side as part of the International Brigade and other groups. Martha Gellhorn, a foreign reporter and Ernest Hemingway’s third wife, later reflected on the conflict: “We knew, we just knew that Spain was the place to stop Fascism. This was it. It was one of those moments in history where there was not doubt.”  Albert Camus added to this viewpoint by writing that “The tragedy of Spain remains to haunt the conscience of the world.”  He was not the only one holding this viewpoint. Between 1936 and 1939, several left-wing intellectuals fought on the side of the loyalists. Two great books, George Orwell’s A Homage to Catalonia (1938) and Ernest Hemingway’s For Whom the Bell Tolls (1940), were written, and Pablo Picasso’s great masterpiece, “Guernica” (1937) was painted. Spain became the first major rallying cry against fascism, as it greatly affected the world, as well as the Labour Party.
After 1937, the Party began to demand that the policy of non-intervention be cast aside, and the the arms embargo against the Spanish Government be lifted. Attlee and others castigated the National Government for “conniving”  at the prolonging of the conflict, and for acquiescing in the face of clandestine Italian and German aggression. When the Foreign Secretary [Anthony Eden] resigned in February 1938, due to differences in foreign policy between himself and the Prime Minister [Neville Chamberlain], Clement Attlee [the Party leader] gave a major speech in Parliament in which he attacked the Prime Minister, saying:
Apparently anything [any type of agreement] is good enough for him. He comes down in triumph to-day and says: “I have a promise that Italy will move her troops out of Spain.” We have become fat on promises during the last 18 months. In regard to Spain, we have had ordinary agreements and gentlemen’s agreements. I do not quite know what the diference is, but neither sort is kept. 
At the end of the speech he accused the National Government of “betraying the cause of peace and the security of [the] country.”  Attlee’s attacks did not subside after this speech. In the debate a few weeks later on the 1938 White Paper on Defence, he lamented that
Collective security is now gone. The objective of the armament programme was set out. The first objective of all was to fulfil our obligations under the Covenant of the League of Nations. Those obligations are gone now. The Prime Minister has told us that the small nations cannot look for protection under the Covenant of the League of Nations. If the small ones cannot look, the big ones cannot look either. 
By this point, he held nothing but contempt for the Prime Minister whom he compared despairingly with Stanley Baldwin [the previous Prime Minister]:
Lord Baldwin [of Bewdley]  was like a king of very fine receiving set— he felt what was happening in the country. The right hon. Gentleman [Chamberlain] does not seem to get much beyond Midland Regional. 
Attlee also held nothing but contempt for the National Government’s decision to maintain the non-intervention policy, despite its being a farce. To show his support for the Spanish Government and the Loyalists, he traveled to Spain in December 1937.
Along with three other National Executive Committee [N.E.C.] members, Attlee visited schools, hospitals, and the battle front around Madrid. There, Attlee addressed a British batallion in the International Brigade, and afterwards gave the clenched-fist salute [a leftist/Communist salute] and allowed the group to call itself the “Major Attlee Company.”  [This last action was the focus of a short-lived Motion of Censure against Attlee.]  When he and the three other participants returned to England, they issued a pamplet entitled What We Saw in Spain. In Attlee’s contribution, which he entitled “Spain Fights for Democracy,” he wrote:
Throughout, the Republic has been greatly hampered by the denial of its right to obtain arms for its defence…. Continued acquiescence in a one-sided non-intervention has made the British Government an accessory to the attempt to murder democracy in Spain. 
This last sentence demonstrates the passionate opinions held by Attlee and others within the Labour Party for the Loyalist cause. Three months later, Attlee gave a scathing speech in Parliament, in which he characterized the National Government’s policy of non-intervention as a:
….grave menace to British interests…. Let me consider for a moment what these British interests are. The first British interest which is menaced is peace. I mean peace, not the uneasy interval between wars, but a permanent and settled peace… The second is the cause of freedom. These causes stand together, and I for my part would not buy peace at the expense of freedom. [emphasis mine] In this country we stand for the peace of a free people. The third interest— they are all bound together— is the safety of this country. I hold that these interests are menaced by the armed intervention in Spain which is being intensified at the present time. The conquest of Spain by the Fascist Powers will endanger the peace, freedom and security of this country. [emphasis mine] 
He criticized the National Government’s Appeasement policy and asked whether it would “see now that there can be no trust in the word of dictators?”  He concluded his speech, saying:
We [the Labour Party] are deeply moved on these benches by the fate of the Spanish Republic and of the people of Spain. I do not deny that in this matter I am a partisan. I am on the side of the Spanish Republic, and I am not the least ashamed of it… You have here [the Spanish Civil War] a breach of international law. You have here an attack on British interests…. The cause of the Spanish Republic is the cause of this country. To betray the Spanish Republic is to betray France, and to betray France is to betray Britain. [emphasis mine] 
Unfortunately for Attlee and other opponents of Franco and fascism, the National Government maintained its non-intervention policy. This policy had proved to be a farce since the beginning; it had enabled Hitler and Mussolini to aid Franco covertly, test new weapons, and develop new fighting tactics while preventing aid from reaching the Loyalists. This was in large part due to the National Government’s unwillingness to risk even the slightest confrontation with Hitler or Mussolini.
 David Clay Large, Between Two Fires:Europe’s Path in the 1930s, (NY: W.W. Norton & Company, 1991), 2nd ed., p. 243, quoting Phillip Knightley, The First Casualty, (NY: 1975), p. 192.
 Ibid., p. 223.
 House of Commons Debates, vol. 310 [310 H.C. Debs.], 30 March 1936, col. 1845.
 332 H.C. Debs., 21 February 1938, cols., 67-68.
 Ibid., col. 72.
 Ibid., 7 March 1938, col. 1661.
 Stanley Baldwin had himself created Earl of Bewdley in1 937, when he retired as Prime Minister.
 Neville Chamberlain was from Manchester, the heart of the Midlands region of England. Attlee was referring to the parochial nature of Chamberlain’s politics and outlook. Churchill referred to Chamberlain once as “a very good Lord Mayor in a lean year.”
 Kenneth Harris, Attlee, (London: Weidenfeld and Nicolson, 1982), p. 138.
 330 H.C. Debs., 13 December 1937, cols. 821-24.
 Harris, pp. 138-39.
 333 H.C. Debs., 16 March 1938, cols. 486-87.
 Ibid., cols. 490-91.
 Ibid., col. 491.