MOSCOW (AP) — Hundreds of demonstrators have gathered outside the parliament building in the country of Georgia to protest the legislature’s failure to pass an elections-reform measure promised by the governing party.

The constitutional amendment would have changed the system of parliamentary elections to entirely proportional beginning in 2020.

The change was a key demand put forth in summer protests that sometimes turned violent.

Bidzina Ivanishvili, head of the Georgian Dream party that dominates parliament had said the party would approve the change. But in a Thursday vote, 37 of the party’s legislators abstained and three voted against, denying the measure the three-quarters support it needed to pass.

Demonstrators later streamed to parliament, blocking the capital Tbilisi’s main avenue.