 Despite the government's promises, the persecution of the Church continued.In response, Pius issued "Acerba animi" on September 29, 1932.As the persecution continued, he issued a letter to the bishops of Mexico, "Firmissimam constantiam", and expressed his opposition and granted papal support for "Catholic Action" in Mexico for the third consecutive time with the use of plenary indulgence on March 28, 1937.