Tsankov formed a new government, which Boris III quickly approved. An uprising by the communists, who had hoped the two major coalition factions would destroy each other, was easily suppressed in September 1923. Nonetheless, dominated by the Macedonian freedom factions and the National Alliance, Tsankov's government failed to restore order. When Tsankov outlawed the Bulgarian Communist Party in 1924, the militant communists led by exiles Georgi Dimitrov and Vasil Kolarov became dominant in that organization. The first response to this change was the bombing of Sveta Nedelia Cathedral in Sofia while the tsar was present in 1925, killing over 100. This attack brought a new government reign of terror against the communists and the agrarians. Disunited Macedonian factions also continued terrorist attacks from their virtually separate state at Petrich, causing alarm in Western Europe. In 1926 Tsankov was replaced by Andrei Liapchev, a Macedonian who remained prime minister for five years.
Liapchev generally was more lenient toward political opposition than Tsankov; the communists resurfaced in 1927 under cover of the labor-based Bulgarian Workers' Party, and an Independent Workers' Trade Union became the center of political activity by labor. IMRO also had much more latitude under the Macedonian prime minister; this meant that political assassinations and terrorism continued unabated. IMRO raids into Yugoslavia ended Bulgarian rapprochement with that country, and the Macedonians demanded preferential economic treatment under Liapchev. But compared with the years preceding, the late 1920s brought relative political stability to Bulgaria. Liapchev led a conservative majority in the subranie and had the confidence of Boris. The press was relatively free, and educational and judicial institutions functioned independently of the government. Industrial and agricultural output finally exceeded prewar levels, and foreign investment increased. But even after substantial reduction, Bulgaria's reparations payments were 20 percent of her budget in 1928, and the return to the gold standard that year weakened the economy one year before the onset of world depression.
In foreign policy, Liapchev tried unsuccessfully to improve British and French World War I reparation terms and bring Bulgaria out of its postwar diplomatic isolation. The country had already improved its international image by participating enthusiastically in the League of Nations, which reciprocated by forcing Greek invasion troops to leave southern Bulgaria in 1926. Boris made two European tours in the late 1920s to strengthen diplomatic ties.
In the late 1920s, the Macedonian independence movement split over the ultimate goal of its activity. The supremacist faction sought incorporation of all Macedonian territory into Bulgaria, while the federalist faction (including the IMRO terrorists) sought an autonomous Macedonia that could join Bulgaria or Yugoslavia in a protective alliance if necessary. Violence between the two groups reinforced a growing public impression that the Liapchev government was unstable.
Data as of June 1992