Given the following passage  "On October 25, 1989, the Supreme Soviet voted to eliminate special seats for the Communist Party and other official organizations in national and local elections, responding to sharp popular criticism that such reserved slots were undemocratic. After vigorous debate, the 542-member Supreme Soviet passed the measure 254-85 (with 36 abstentions). The decision required a constitutional amendment, ratified by the full congress, which met December 12–25. It also passed measures that would allow direct elections for presidents of each of the 15 constituent republics. Gorbachev strongly opposed such a move during debate but was defeated.",  answer the following question. Note that the answer is present within the text.  Question: What pressured the 542 member group to make consitutional changes?
Answer:
sharp popular criticism