A secret high-level report has revealed overnight that NSW top transport officials were warned to delay the recent timetable changes for Sydney’s rail network, several months after experts warned there was a “substantial risk of failing to deliver the level of performance which the public expect”.

The report warned there was ‘little room’ for rail systems to fail and also revealed tensions and resentments between the transport agencies.

Concerns were also raised over particular groups of passengers being disadvantaged which limited the amount of information shared between the lead agency, Transport for NSW, and Sydney Trains.