With respect to the arbitration decision itself, Mamatey writes that "On 25 March, to expedite the work of the peace conference, the Council of Ten was divided into the Council of Four (The "Big Four") and the Council of Five (the foreign ministers). Early in April the two councils considered and approved the recommendations of the Czechoslovak commission without a change – with the exception of Teschen, which they referred to Poland and Czechoslovakia to settle in bilateral negotiations." When the Polish-Czechoslovak negotiations failed, the Allied powers proposed plebiscites in the Cieszyn Silesia and also in the border districts of Orava and Spiš (now in Slovakia) to which the Poles had raised claims. In the end, however, no plebiscites were held due to the rising mutual hostilities of Czechs and Poles in Cieszyn Silesia. Instead, on 28 July 1920 the Spa Conference (also known as the Conference of Ambassadors) divided each of the three disputed areas between Poland and Czechoslovakia.