A £700,000 scheme to place security guards on Birmingham buses has become bogged down by legal problems.
Birmingham City Council announced in February that it intended to recruit wardens to travel on troubled- prone routes.
The initiative was described by the council's Conservative-Liberal Democrat leadership as a key part of a package of measures to tackle vandalism and yobbish behaviour.
Four months later, the project is still not off the ground.
Travel West Midlands (TWM), the region's biggest bus company, is yet to hold detailed talks with the council about the way the wardens might operate.
Company spokesman Phil Bateman said TWM questioned the effectiveness of the proposal, since only bus drivers and police officers have the legal powers to ask a person to leave a bus.
There had only been " tentative contact" between TWM and the council, he admitted.
Mr Bateman added: "The Birmingham City Council initiative is still not much more than that at the moment. The detail of the way that the scheme will work has yet to be fully announced to us."
TWM want to know how the wardens would work with a safer buses project recently announced by the transport authority, Centro, and West Midlands Police, which will see teams of community police officers and full-time officers travel on selected routes.
Mr Bateman added: "As a company we are always looking to work together with local authorities, however in this case the detail of the council initiative has yet to be discussed with us. We look forward to seeing what powers this team will have, and how they will be organised to be effective, how they will operate and what will be their limit of responsibility.
"None of these details have been made known to us as yet."
Len Gregory, cabinet member for transportation, told a meeting of the full city council last week that he was in discussions with Centro about bus wardens.
Coun Gregory (Con Billesley) said he was hopeful of agreeing a "combined effort" with Centro and TWM that would enable people to travel in safety on buses in Birmingham.
He is to hold talks with Phil White, the chief executive of National Express, the parent company of Travel West Midlands.