The Ottaviani Intervention or Short Critical Study on the New Order of Mass was a study of 5 June 1969 written by twelve theologians who worked under the direction of Archbishop Marcel Lefebvre. Cardinals Alfredo Ottaviani and Antonio Bacci sent it to Pope Paul VI with a covering letter of 25 September 1969. The study cast doubt on the orthodoxy of the Mass of Paul VI, which had been promulgated by the Apostolic Constitution Missale Romanum of 3 April 1969, though the definitive text, which took account of some of the criticisms of the Short Critical Study, had not yet appeared.
Pope Paul VI asked the Congregation for the Doctrine of the Faith, the department of the Roman Curia that Ottaviani had earlier headed, to examine the Short Critical Study. It responded on 12 November 1969 that the document contained many affirmations that were "superficial, exaggerated, inexact, emotional and false".
A letter of 17 February 1970 signed by Cardinal Ottaviani and addressed to Dom Gerard Lafond, O.S.B., was published in La Documentation catholique] 67 (1970), pp. 215-216 and 343. It stated:
I have rejoiced profoundly to read the Discourse by the Holy Father on the question of the new Ordo Missae, and especially the doctrinal precisions contained in his discourses at the public Audiences of November 19 and 26, after which I believe, no one can any longer be genuinely scandalized. As for the rest, a prudent and intelligent catechesis must be undertaken to solve some legitimate perplexities which the text is capable of arousing. In this sense I wish your "Doctrinal Note" [on the Pauline Rite Mass] and the activity of the Militia Sanctae Mariae wide diffusion and success.
The letter also expressed regret on the part of the cardinal that his letter of 25 September 1969, which he did not disown, had been published:
I regret only that my name has been misused in a way I did not wish, by publishing a letter that I wrote to the Holy Father without authorizing anyone to publish it.
Jean Madiran, a traditionalist Catholic who is now editor of the daily newspaper Présent, close to the French Front National, but who was then director of the review Itinéraires, which was condemned by the French episcopate in 1966, maintained that Itinéraires had received the cardinal's authorization to publish his letter to the Pope and suggested that Ottaviani had signed the letter to Dom Gerard-Marie Lafond, prepared by his secretary, without knowing its contents, since he was blind, as he had been already when he signed his letter to the Pope.