Complex sentence: Therefore Moscow ordered the puppet government of Paleckis to carry out elections for a "People's Seimas" on 14--15 July with a single list of candidates containing only Communists and their allies.
Split into simpler sentences: Therefore Moscow ordered the Paleckis government to carry out elections for a "People's Seimas" on 14--15 July. Voters were presented with a single list of candidates containing only Communists and their allies.