A vote of no confidence in Bristol's biggest bus operator is to be tabled by politicians who claim the public were not consulted over changes.
First Bus is re-routing several bus services, re-numbering various routes, changing timetables and increasing some late night travel from 1 September.
City councillors are to discuss the motion at the next full council meeting on 10 September.
First Bus said "overall service changes had been overwhelmingly well received".
Conservative politicians claim the bus company refused to negotiate over the changes and say Bristolians have had "enough of being treated in such a cavalier fashion".
Tory leader, councillor Peter Abraham said: "What my motion is saying, very clearly, is that the recent moves and the way you've done it, your inability to engage and consult.
"The very first we heard about this, as councillors, was to receive a highly confidential memo.
"We were told about the changes but we couldn't even talk to our constituents about it.
"I wrote in protest and said 'what's the point of sending me this if it's confidential?'"
Paul Matthews, from First Bus, said: "We are disappointed that councillor Abraham is proposing to table a vote of no confidence at the next full council meeting.
"We are committed to working with our local stakeholders and partners within the council to improve the public transport experience for our customers and to meet Bristol's transport needs."