Brasilia: Congressional police in riot gear used tear gas to drive back hundreds of members of federal police unions who tried to invade the Brazilian Congress on Tuesday to protest a pension reform bill that would reduce their benefits.

The demonstrating police officers broke glass doors before being pushed back in a violent clash that underscored the unpopularity of the pension reform that is at the heart of Temer's austerity program.

Police officers attempt to break into the Brazilian National Congress during a protest by officers from several Brazilian states against pension reforms. Credit:AP

The program aims to rescue the Brazilian economy from its deepest recession on record. Riot police used tear gas and stun grenades to disperse fellow officers from the front doors of Congress.

Earlier Temer had made new concessions to ease the bill's passage. He agreed to set a lower retirement age for women, police, teachers and rural workers and grant more generous transition rules for workers after allies' concerns delayed the bill's formal presentation.