The Workers’ Party had fielded former President Luiz Inacio Lula da Silva as its candidate in the election and he was considered the front-runner until he was barred from running after being jailed for corruption and money laundering.
The party said in a statement that it recognizes the legitimacy of the results of the vote but will boycott the inauguration due to the electoral process itself.
“The illegal prohibition of the candidacy of former president Lula and the criminal manipulation of social media to spread lies against candidate Fernando Haddad” favored the far-right leader in the elections, it said.
Both the Workers’ Party and the Socialism and Liberty Party said the decision was also an act of resistance to Bolsonaro, who has angered many with comments seen as homophobic, racist or offensive to women, as well as expressing nostalgia for Brazil’s 1964-1985 military dictatorship.
Also Friday, Brazilian authorities said security preparations for the inauguration are the most comprehensive ever.
The Secretary of Public Security in Brasilia told the Associated Press that they are expecting as many as 500,000 people to attend the ceremony.
Brazil’s military has deployed anti-aircraft missiles and fighter jets to protect the event from the air. On the ground, more than 3,000 police and military will take to the streets.
Security around Bolsonaro has been elevated following a Sept. 6 knife attack that left him with a ruptured intestine.