As part of £262m in cuts planned over the next four years, Lancashire County Council is proposing to scrap the Day Care Transport scheme, which is used by 891 people.
It says the “very difficult decision” could save around £2.75m a year from 2017/18, with passengers being consulted and helped to find alternative means of transport.
But users say axing the service would put “unbearable strain” on the families and carers of disabled and elderly people, and have collected nearly 8,000 signatures on a petition.
Petition organiser Paul Taylforth, 58, whose disabled son John uses the service five times a week, said: “Lancashire County Council says it will protect the most vulnerable.
“Yet this policy flies directly in the face of that promise.”