Shout out to Calgary’s Future for this template: Save the Green Line | Calgary's Future
You could probably add something about reinstating funding, and not giving up on the project.
I personally added things from the perspective of youth, affordability, and climate action.
It would be easy to just give up hope at this point, but this project is so important, as is transit overall, to so many Calgarians. Please take a second and send an email!