SÃO PAULO—The acting president of Brazil’s lower house moved to annul the impeachment process against President Dilma Rousseff, a move the president of the Senate said wouldn’t alter that body’s plan to vote later this week on trying Ms. Rousseff.

Waldir Maranhão, the acting president of the Chamber of Deputies, on Monday said he had overturned the body’s April 17 decision to send the impeachment process to the Senate for a possible trial. Mr. Maranhão opposed impeachment in last month’s vote, which he alleged on Monday was...