He became vicar of Saint-Vougay in 1904, where he undertook the patronage of Paotred Sant-Nouga, where he formed study circles, a choir, and a theatre troupe for the local youth.
Perrot founded Bleun-Brug (Heather Flower) in 1905, which soon absorbed the magazine Feiz ha Breiz (Faith and Brittany), which he edited after 1911.
He was initially stationed in a conservative Saint-Vougay parish, but was transferred to the more leftist area of Scrignac in 1930 by the episcopal hierarchy, who disliked his political activities.
According to Henri Fréville, on 7 August 1943 Perrot was questioned about the movements of members of Bagadou Stourm, Breton nationalist stormtroopers allied to the Nazis, who had stopped at Scrignac.
He was hospitable toward the Bagadou Stourm Youth, who were most active around Finistère, where leaders such as Yann Goulet and L'Haridon had been arrested by the French police but released by the Germans.
On 12 December 1943, aged 66, the abbé was killed by Jean Thépaut, a member of the French Communist Party, after a series of denunciations of Perrot for alleged collaborationist activity.
His role of has been the source of much controversy about "the "Breton cause", notably between Ronan Caouissin and the director of the theatre troupe Ar Vro Bagan.
Yvon Tranvouez, in Bretagne et identités régionales pendant la Seconde Guerre mondiale asserts that The abbé Perrot was one of the "new crusaders" (...) who, out of phobia of communism, were forced to admit the logic of collaborating with the Germans, seen as the lesser of two evils.
[1]Abbot Henri Poisson said in his book: The assassination of abbé Jean-Marie Perrot, on 12 December 1943, well-known, and to whom one could not reproach but his ardent loyalty to Brittany, constituted a hateful crime and cannot be explained by the regime of anarchy and totalitarianism which marked this period.
[2]Francis Gourvil in 1990: Abbé Perrot was well-known for his ties with the Breiz Atao who themselves... from there jumping to the conclusion that he was responsible of the second arrest of D. is not far-stretched...
Unfortunately, he had close friends, you know who I'm thinking of, to whom he might have mentioned the matter in question, quite innocently, and this, added to other facts (...) everything was transmitted to Quimper and recorded, systematically, by the one who centralised information of interest for the Gestapo in this town.