Drivers have said it is "totally out of order" for Lothian buses to blame delays and disruption on roadworks and crowds with the issues caused by a severe driver shortage.
Lothian are up to 200 bus drivers short of a full roster which has lead to vehicles being taken off the road, passengers left stranded before terminus points and backroom staff behind the wheel.
In August, Lothian said it could not cope with the additional crowds caused by the Festival and roadworks which the company said caused significant delays and disruption.
The issues were instead blamed on poor management from managing director Richard Hall and a driver shortage.
Drivers are also beginning to fear for their safety as the relationship between passengers and drivers sour as cancellation numbers rise.
The inability of the company to hire adequate staff numbers for the frontline city bus service has led to hundreds of buses being taken off the road over the summer.
On the weekend of 5 and 6 September, more than 40 buses were off the road each day due to a lack of staff causing several delays and cancellations.
Meanwhile, managing director Richard Hall was away in Blackpool for the Bus Driver of the Year awards, along with five drivers, the equivalent of 15 shifts which would have mitigated cancellations.
One driver, who wished to stay anonymous, said it was now a common occurrence for buses to decant their passengers to the side of the road before driving the bus back to the depot, rather than changing drivers.
This leaves an entire bus of passengers on the side of the road waiting for a new bus, solely due to the lack of a driver to take over the shift after another has hit their maximum driving hours.
It has also been claimed that the Lothian training centre has not supplied one driver to the city bus service in 14 months, instead choosing to staff Lothian Country and Eastcoastbuses as the company expands.
The driver said: “At least eight shifts per day are on offer as overtime in just one garage.
“The statement saying Lothian can not run the service because of roadworks just does not bear weight.
“To blame roadworks is totally out of order.”
Another anonymous Lothian source said: “There are supervisors and driving backroom staff out on routes. They are getting hell for the problems.
“I don’t think it is too long before a driver is assaulted, and it is wrong for the company to blame roadworks. I’ve heard supervisors say that it is embarrassing to say ‘I work for Lothian buses.’
“It really is disgusting what is happening. Every single depot has not been able to meet the level of service the traffic commissioner requires.”
A spokesperson for Lothian said: “Significant demands were placed on Lothian services during the summer period, and our appreciation is expressed to our drivers and staff, many of whom worked overtime, for their brilliant efforts to keep Edinburgh moving.
“Our ongoing programme of driver and staff recruitment and training is continuing in the coming months and this will help to ensure that Lothian continues to maintain its high levels of customer satisfaction.”