Staff on Virgin Trains East Coast trains will stage a two-day walkout over threat to guards, stations and travel centre roles, the RMT Union confirmed.
The strike, which will be held on 28 and 29 April, comes after the union warned it wanted "explicit clarification" by the company over the role of train guards.
"The only response the company has offered is to repeat the vague and non-committal mantra of 'within our discussions we have confirmed that the safety-critical duties of the guard will remain on the train'," an RMT statement released on Thursday (13 April), said.
"This mealy-mouthed form of words gives no reassurance to RMT members in the front line nor any protection from the possible introduction of driver-only operation."
The union said consultation over widespread on-board changes has been going on for over a year and that it has told already told the rail operator the proposed changes will not work.
However, Virgin implemented the changes from 31 March, despite seemingly not having reached an agreement with the union. RMT claimed the new service is not fit for purpose and "has turned into a chaotic shambles", with untrained staff forced into roles.
"It is simply appalling that Virgin East Coast have refused to give the most basic assurances on the safety-critical role of the guard on their trains continuing into the future," said RMT General Secretary Mick Cash.
"Instead they have sought to fob us off with meaningless statements that are frankly an insult to the intelligence of our members who are charged with maintaining safety on-board these inter-city trains."
The union also drew attention to the increasing number of complaints from passengers, which were met by Virgin blaming staff sickness for problems on its own Twitter feed.
"This contemptuous attitude has unleashed a tidal-wave of anger at the grass roots and the action we have agreed to put on is simply a reflection of the disgust and frustration at months of ducking and diving by Virgin/Stagecoach," Cash added.
Virgin, which operates services between London, north-east England and Scotland, said that it is yet to receive a formal notification from the union.
The RMT is facing similar disputes with Southern, Merseyrail and Arriva Trains North and its members with the three rail operators, staged a 24-hour strike last Saturday.