KIEV, April 21 – Lawmakers may get together for an emergency session of Parliament before May 13 to try to approve controversial amendments to the constitution that undermine the authority of the president, a lawmaker said Monday.

The timeframe disclosed by Adam Martyniuk, a senior member of the Communist Party, which backs the amendments pushed by Prime Minister Yulia Tymoshenko, provides a glimpse at a timetable for the pro-Western coalition collapse.