The comments came as the Greenock business said that efficiency improvements had helped it almost triple pre-tax profits to just under £1.4 million despite turnover dipping slightly to £37.9m.
Managing director Ralph Roberts said the bus network receives “peppercorn levels of infrastructure investment” despite delivering 74 per cent of public transport journeys.
“We are talking to government at a national level to release more funding for the bus user but local government sees this as high risk as it will bring voter backlash from car users.
“Local politicians need to remember that bus users are also voters,” he said.
McGill’s said passenger numbers had been declining since 2015 with factors also including the high street malaise.
Board director Sandy Easdale added: “Given the climate emergency now declared, local authorities need to prioritise the bus over the car. Buses are the answer to congestion and poor air quality whereas the car is the cause of them.
"We need more bus shelters, more parking management and better road works management which will contribute to healthier and wealthier lives for the public.”