A controversial tweet about democracy has sparked sharp criticism of the son of Brazil's president, Carlos Bolsonaro.

"The change that Brazil wants will not come as soon as we want by democratic means," Rio de Janeiro city councilor and son of the president, Jair Bolsonaro, said in a tweet.

The criticism came from both political allies and public critics alike.

Vice President Hamilton Murau said on Tuesday that democracy is fundamental and fundamental.

Senate President Duffy Colombo said Bolsonaro's tweet deserved contempt.

"Only with democracy can we have a free and sovereign state. There is no other way for our state," said Sao Paulo Governor Joao Doria.

"Democracy is not granted, but it is taken away from us to ensure that statements are not accepted outside the constitutional system," said Philippe Santa Cruz, president of the Bar Association.