Brazilians saying that President Jair Bolsonaro is doing a “bad or terrible” job rose to 38% from 33% previously, in the first major poll since the government faced global outcry over its handling of record fires in the Amazon rainforest.
The Datafolha polling institute found that 29% say that Bolsonaro is doing a great or good job, down from 33% in July, according to the poll published on Monday.
That is the lowest level of approval for a president since Brazil returned to democracy, below the 34% of respondents in June 1995 who said that then-President Fernando Henrique Cardoso was doing a good or great job.
Brazilians who said the Bolsonaro was doing a normal job fell to 30% from 31% previously, within the margin of error.
Datafolha found that 51% of Brazilians thought Bolsonaro had done a bad or terrible job responding to the Amazon fires.
Last month, Brazil's space research agency INPE revealed that the highest number of forest fires were tearing through the Amazon rainforest since 2010, sparking international outcry demanding that the country do more to protect the world's largest tropical rainforest.
Bolsonaro authorized the military to fight the fires after several days of public protests and criticism from world leaders.
The far-right firebrand also engaged in a public war of words with French President Emmanuel Macron, who called the fires ecocide and for more to be done to combat them as Group of Seven wealthy nations met in France.
Bolsonaro ultimately said that he would only accept a funding offer in aid if Macron withdrew insults against him.
Datafolha found that 66% of Brazilians said that Brazil should be accepting international aide to combat Amazon deforestation.
Bolsonaro won the presidency last year with a commanding lead but has seen his support steadily erode since taking office on Jan 1.
The Datafolha institute polled 2,878 people in 175 towns across Brazil on Aug 29 and 30. The poll has a 2 per cent margin of error.