The renovation of Maracana, the centerpiece stadium of the 2014 World Cup, stopped Monday because of a labor dispute.
Workers were not on the job and are threatening a full strike beginning next week if demands are not met for higher salaries and better meal vouchers and health plans.
Negotiations with the construction companies already have begun. The union says the workers are expected to return Tuesday, but a strike could start as early as Monday if their demands are not taken into consideration.
The renovation is behind schedule — it originally was expected to be completed in December. The famed Rio de Janeiro stadium will host three matches during the Confederations Cup in June, including the final. It will also be the site of the World Cup final.