Marvin Rotrand, the city councillor from Snowdon, is no longer vice-chair of the STM.
Rotrand, who has been a councillor since 1982, was appointed vice-chair of the STM in 2002, but apparently removed from that post at the behest of Mayor Denis Coderre.
"I'm not exactly sure what it is that I did to piss him off," said Rotrand.
Rotrand told CTV News that he only found out by happenstance.
"I haven't been notified. I found out about it accidentally because I texted my director general and he texted back saying look, he just found out the news, very sorry, he doesn't want to lose me but it's not his call," said Rotrand.
On his way into Monday evening's council meeting, Rotrand said some members had expressed their sympathies.
"A member of the Executive Committee who will go unnamed came up to me and said 'look, I'm really sorry, this is really unfair,'" said Rotrand.
He added that on the weekend he saw the CDN-NDG borough mayor Russell Copeman, who is also on the Executive Committee, and was told the mayor's cabinet never discussed his position at the STM.
"This is Denis Coderre's personal decision," said Rotrand.
Rotrand was elected as a member of the Coalition Montreal party, which supported Marcel Coté's bid to become mayor. Rotrand is now the interim leader of the party.
Later on CTV confirmed another former Coalition Montreal member had lost their appointed post.
Benoit Dorais, who led Coalition Montreal following Coté's death, and who joined Projet Montreal within the past month, is apparently going to be removed from his position as chair of the Agglomeration Council.
The Agglomeration Council includes the Mayor of Montreal, 15 Montreal councillors, and 14 mayors of the demerged cities as well as an extra councillor from DDO.
Dorais, who is mayor of the SouthWest borough, was courted by Coderre's party before deciding to join Projet Montreal.
On Tuesday, Elsie Lefebvre, a former Coalition Montreal councillor, was named vice-chair of the STM.
Projet Montreal councillors were dismissive of the moves.
"It's absolutely partisan, party politics on the part of Mayor Denis Coderre. That's the way Coderre operates," said Alex Norris.
Sterling Downey said the motive behind the moves was clear to those who can read between the lines.
"I also think that the mayor is sending a loud message to all the rest of the councillors on the floor to reconsider or rethink what team they're going to join in the coming elections," said Downey.
Municipal elections take place in November.