By June 1947 the Communist Party had gutted the Smallholders' Party as a political force through the mass arrests and forced exile of its main leaders and had gained effective control of the government, installing a fellow traveller as Prime Minister. New elections in August 1947 increased the Communists' share of the vote, though non-Communist parties won essentially the same number of votes as in 1945 and the elections were marred with fraud and intimidation. Regardless, further Communist machinations and intrigues managed to liquidate most of the remaining opposition parties within the next year. This culminated in their merger with the Social Democratic Party of Hungary in June 1948 to form the Hungarian Working People's Party; essentially an expanded Communist Party under a new name. The government instituted programs of nationalization of key industries as part of the Sovietization of the Hungarian economy and society as the country entered the Soviet sphere of influence. In August 1949, the country was formally proclaimed to be a people's republic with the Communists as the sole legal party. This arrangement would last, aside from a brief break in 1956, until the end of Communism in Hungary in 1989–90.