A three-day strike involving Northern rail staff is due to take place next month.
The Rail, Maritime and Transport union (RMT) has announced fresh industrial action will take place on Saturday July 8, Sunday July 9 and Monday July 10 as part of its long-running dispute with Arriva Rail North - which runs the Northern franchise - over the future role of guards on trains.
Northern rail services operate across parts of Derbyshire, Nottinghamshire and Lincolnshire.
The union said it was "angry and frustrated" that its attempts to broker future talks over the issue of driver-only trains - where drivers are responsible for operating carriage doors - had been blocked by the company's unreasonable demands.
RMT General Secretary Mick Cash said: “The sheer intransigence of Arriva Rail North means that we have no option but to confirm a further round of strike action. The responsibility for the inevitable disruption lies wholly with the company.
"We are angry and frustrated that Arriva continue to face up to the facts and also continue to ignore a perfectly reasonable union proposal to invite the DfT to join us in three-way talks aimed at finding a solution.
"Instead, they have chosen to up the ante by demanding that RMT attends talks solely to discuss the implementation of plans the company know we are wholly opposed to. That is a total disgrace.
“The public, who support RMT’s campaign for a guarantee of a guard on their trains, will be appalled that Arriva Rail North have failed yet again to offer any kind of progress whatsoever in the talks and have instead opted to try and bulldoze through their plans regardless. It is that flagrant disregard for the safety issues at the heart of the dispute which leaves us with no option but to press on with the campaign of strike action.
“RMT commends our Arriva Rail North Members on their rock solid display of strength, resolve and unity during the action so far in opposition to the introduction of driver controlled operation and defence of the guards to guarantee a safer, securer and more accessible railway for all.
“The union continues to remain available for meaningful discussions with the company in order to seek a satisfactory resolution to the on-going dispute.”
Picket lines are being planned at locations across the Northern routes, the RMT added.
Northern said it expected to operate a reduced service during the strike action, and advised customers to allow more time for their travel and to consider whether their journey is necessary.
Richard Allan, Northern's deputy managing director, said: “We are deeply disappointed and hugely frustrated that RMT is choosing to cause more pain for our colleagues and customers rather than get round the table to talk first.
"Only this week we wrote to RMT again, urging them to engage in meaningful modernisation talks with us. We have been clear that for all our conductors we are prepared to guarantee jobs and current pay, and continue with annual pay reviews, if we can reach agreement with RMT.
“The RMT’s dispute will be solved by talking, not by unnecessary strike action which impacts our customers, our employees, businesses and the economy of the North. Should the RMT strike action go ahead, we are committed to keeping our customers on the move as much as possible.”
Northern operates passenger services across the north of England, including in the High Peak from Manchester Piccadilly to Buxton, and between Manchester and Glossop/Hadfield. It also serves stations through the Hope Valley, between Sheffield, Chesterfield and Nottingham, and on the line from Sheffield to Worksop, Retford and Gainsborough.