In 1939-1945 the chief exponent of Czechoslovakism was the London-based Czechoslovak government in exile led by Jan Šrámek and especially by the president in-exile, Edvard Beneš; Czechoslovakism was popular also among some sympathetic British historians, like Seton-Watson. Officially the exile Czechoslovak structures not only refused to recognise the post-September-1938 political changes but they also stuck to the theory of one, Czechoslovak nation; it was advanced as late as in mid-1943. When negotiating with Moscow-sponsored Czechoslovak Communists Beneš advocated return to Czechoslovakism as to a state doctrine, though KSČ at that time was already highly sceptical about viability of the concept. Also the (SNR), underground body formed in Slovakia, styled as continuation of the pre-1939 autonomous Slovak assembly, politically heterogeneous though strongly left-leaning and declaring loyalty to president Benes, adopted a different position. The body, formally the supreme political organisation leading the Slovak National Uprising, in its September 1944 pronouncement spoke in favour of Czechoslovakia as the state of two nations, the Czechs and the Slovaks.