Greater Anglia is being urged to hold fresh talks with rail unions in a bid to prevent threatened industrial action.
The Rail, Maritime and Transport union has written to a number of operators warning of a "crisis" in the industry over the scaling back of renewal works and jobs.
The union is preparing to ballot members at Greater Anglia - which runs services in Norfolk, Suffolk, Essex, Cambridgeshire and Hertfordshire - over fears driver-only trains could be introduced.
It is also embroiled in disputes at Northern, Southern and Merseyrail, which have already led to a series of strikes.
The RMT met Transport Secretary Chris Grayling last week to discuss the disputes.
Greater Anglia insists it has no plans to scrap conductors on its intercity trains and rural routes - insisting they are "highly valued colleagues".
But the RMT says the operators Dutch owner, Abellio, will not guarantee a second qualified person on every train.