https://twitter.com/AndrewLawton/status/1495433223698063363
This is the innermost perimeter. Police are allowing journalists in, but only those with “credentials.” I offered ID and letter of assignment from editor which was not accepted. Appears from seeing others go through that only Parliamentary Press Gallery membership suffices.
https://twitter.com/RebelNewsOnline/status/1495433500735987713
Today Ottawa police wouldn't let our reporter film in downtown Ottawa saying that she doesn't have press credentials and rejected her Independent Press Gallery card because “It’s a laminated piece of paper you could have made at home.”
This will accelerate distrust of properly credentialed media.
Just to clarify do you mean from that group? Your use of "of" could be interpreted as a distrust towards the group.
Paraphrase: "This will accelerate increasing lack of trust in properly credentialed media."
Hope that helps.