The bitter dispute over the role of guards and driver-only trains has spread to East Anglia after another vote for strikes.
200 rail guards, who are members of the Rail, Maritime and Transport union on Greater Anglia, backed industrial action by nine to one on a 90% turnout.
Drivers backed strike action by a two to one margin.
The union has staged a series of strikes on Southern Railway, Merseyrail and Arriva Rail North, while workers on the new South Western Railway franchise are to be balloted for strikes over the same issue.
Greater Anglia has always maintained that there would still be a role for conductors on new generation trains where the doors are operated by the driver.
Greater Anglia operates the Intercity rail line between Norwich and London along with a number of branch and rural lines in Norfolk, Suffolk, Essex, Hertfordshire and Cambridgeshire.
Greater Anglia is replacing its entire fleet with brand new trains during 2019/20.
The company says they will be fitted with the latest modern technology, allowing drivers to open and close doors, as endorsed by two safety reports from two independent organisations.
The RMT said Abellio, which runs Greater Anglia, had failed to provide theunion with assurances over the role and responsibilities of guards.
The ballot result will now be considered by the RMT's executive who will decide on the next steps in the dispute.
"Greater Anglia have been given every opportunity to give a guarantee on the future role of the guards on their services.
Greater Anglia said the driver operating the train doors would improve both safety and punctuality, as well as freeing up conductors for more customer service duties.
“We are obviously disappointed with the ballot result. We’re keen to talk to the RMT to try and resolve the issues involved and to avert industrial action.
Greater Anglia says 60% of its rail services already operate with only a driver and no conductor.
Greater Anglia routes where all trains operate with both a driver and a conductor
Norwich to London intercity service
Norwich to Sheringham
Norwich to Great Yarmouth
Norwich to Lowestoft
Norwich to Cambridge
Ipswich to Lowestoft
Ipswich to Felixstowe
Harwich/Ipswich to Cambridge
Ipswich to Peterborough
Marks Tey to Sudbury
Colchester to Clacton/Walton
Manningtree to Harwich.