Speaking from the US, I've known some Catholic Workers Movement people here and there. There aren't many, but they mean well.
There's a church out in San Francisco called GLIDE that used to be a part of the UMC. They're certainly not revolutionary socialists, but they do some genuinely good work. They have one of the largest soup kitchens in the US, as far as I'm aware. They serve breakfast, lunch, and dinner, and give out literally hundreds of meals a day, every single day. They also do clean needle exchanges and quite a lot of other programs.