The internal economic crisis of 1927 intertwined with a sharp exacerbation of the foreign policy situation. On February 23, 1927, the British Foreign Secretary sent a note to the Soviet Union demanding that it stop supporting the Kuomintang–Communist government in China. After the refusal, the United Kingdom on May 24–27 broke off diplomatic relations with the Soviet Union. However, at the same time, the alliance of the Kuomintang and the Chinese Communists fell apart; on April 12, Chiang Kai-shek and his allies massacred the Shanghai Communists. This incident was widely used by the "united opposition" (the "Trotsky-Zinoviev bloc") to criticise the official Stalinist diplomacy as deliberately a failure.