ATHENS, Greece - June 15, 2011 - Thousands of Greek protesters surrounded the Parliament building in Athens on Wednesday as a general strike paralyzed the country and the prime minister held emergency talks on a controversial reform package.

Riot police and barricades blocked approaches to Parliament as 20,000 people gathered in the capital, summoned by a popular protest group that has occupied central Syntagma Square for weeks after a similar mobilization in Spain.

Lawmakers inside the building are debating a new austerity package worth over 28 billion euros ($40 billion), a condition demanded by Greece's creditors in return for a badly-needed new aid bailout.

Prime Minister George Papandreou began an emergency meeting with the Greek head of state, President Carolos Papoulias, after a government deputy defected on Tuesday, reducing the government's majority to five seats.

Another party member also recently indicated that he would vote against the government's plan, raising the likelihood the reforms may be rejected.

A similar event in Portugal prompted the collapse of a left wing government followed by snap elections that were won by a right-of-center party.

Reports said the government may seek to force opposition deputies to shoulder some responsibility for the reform package by setting a minimum majority for its passage of 180 votes in the 300-seat body, 25 more than the ruling party holds.