Brazil's President Dilma Rousseff says she is "outraged" at attempts to impeach her and has a clear conscience.
Speaking after the lower house of Congress voted to begin impeachment proceedings against her, she said she had done nothing wrong.
She is accused of manipulating government accounts, which she denies.
Speaking calmly and in a measured way, she said she would fight "the injustice" she was facing and would not bow to pressure.
Lower house defeat
Lawmakers in the lower house of Congress on Sunday voted overwhelmingly in favour of sending an impeachment motion against her to the upper house.
The Senate will now have to decide whether to start an impeachment trial. Senators are expected to vote on the matter early next month.
Polls conducted by Brazil's major newspapers suggest a majority of the senators will vote in favour of the trial.
If that happens, Ms Rousseff will be suspended from office while the trial is under way.
Vice-President Michel Temer will become acting president for the duration of her suspension.
Ms Rousseff had harsh words for Mr Temer, whom she accused of openly conspiring against her.
Mr Temer is a member of the Brazilian Democratic Movement Party (PMDB) which until recently was in a coalition with Ms Rousseff's Workers' Party.
But just weeks before Sunday's impeachment vote, the PMDB left the coalition and its leadership voted to support the impeachment proceedings against Ms Rousseff.
Many Brazilian newspapers featured a photograph of Mr Temer on Monday, showing him smiling as he watched the votes against Ms Rousseff being cast in the lower house.
Ms Rousseff said she had the "spirit, strength and courage" to fight those plotting against her.
She said that she had not committed any actions which warranted her impeachment.
She argued that presidents who had preceded her had engaged in fiscal manoeuvres similar to those she is accused of and no one had ever found fault with it.
The president said that the moves to impeach her were a power grab by those who did not have the votes to get the top job democratically.
Referring to her youth as a left-wing activist fighting Brazil's military rule, she said: "I spent my youth confronting the dictatorship, now I'm confronting a coup d'etat."
She said she would continue fighting "the injustice" committed against her.
Sources from the presidential palace said on Monday that she had cancelled her planned travel to New York, where she was due to attend a United Nations climate event this week.