(Adds announcement of a second strike)
LONDON, April 13 (Reuters) - Train services in northern England and on a major rail link to Scotland will be hit later this month when members of the RMT union go on strike in a long-running dispute over staffing.
The action will affect Virgin Trains East Coast (VTEC) which operates services on the main link between London and Edinburgh, and Arriva Rail North.
The dispute over whose job it should be to open and close train doors has already caused widespread disruption on Southern rail, a major commuter route into London.
RMT staff on VTEC, a joint venture 90 percent owned by Stagecoach, are set to strike on April 28 and 29.
Those on Arriva Rail North, which serves Liverpool, Manchester and Newcastle, will strike for 24 hours on April 28, the RMT said on Thursday.
The union said VTEC had not offered sufficient reassurances that train guards would keep their roles and had failed to allay its concerns over a possible switch to driver-only trains, following changes to staffing introduced last month.
Virgin Trains said the staffing changes would benefit passengers and had no impact on safety. It planned to run a near-normal timetable during the strike.
There was no immediate comment from Arriva.
(Reporting by Alistair Smout; editing by Stephen Addison)