Thousands of demonstrators have gathered outside the Ukrainian parliament shouting "revolution" as MPs met for what could be a vote of no-confidence in the government, the Associated Press said.

Parliament is to discuss the violence and chaos of the past several days stemming from massive demonstration denouncing president Viktor Yanukovych's decision to shelve signing an agreement with the European Union deepening economic and political ties. Riot police have reacted violently against demonstrators several times.

After the general discussion, parliament will consider whether to put an opposition-backed no-confidence motion to a vote.

If a vote is held, it is unclear if the opposition has enough support to pass it. Several MPs from the governing party have defected.