Industrial action will take place on 13, 14, 16 and 17 December and on 3, 4, 6 and 7 January.
The RMT has also issued an overtime ban across the railway network from 18 December-2 January.
It will follow a strike this Saturday, 26 November, from members of the train drivers’ union, Aslef, working for 11 train operators.
Of the next tranche of walk-outs, RMT said in a statement: “Despite every effort made by our negotiators, it is clear that the Government is directly interfering with our attempts to reach a settlement.
“The union suspended previous strike action in good faith to allow for intensive negotiations to resolve the dispute.
“Yet Network Rail have failed to make an improved offer on jobs, pay and conditions for our members during the last two weeks of talks.
“At the same time Rail Delivery Group, representing the train operating companies, have also broken a promise to make a meaningful offer on pay and conditions and even cancelled negotiations that were due to take place yesterday.”
RMT general secretary Mick Lynch said: “This latest round of strikes will show how important our members are to the running of this country and will send a clear message that we want a good deal on job security, pay and conditions for our people.
“We have been reasonable, but it is impossible to find a negotiated settlement when the dead hand of Government is presiding over these talks.
“The employers are in disarray and saying different things to different people, sometimes at the same time.
“This whole process has become a farce that only the new secretary of state can resolve. When I meet him later this week, I will deliver that message.”
Mr Lynch added that the union was “sorry to inconvenience” the public this Christmas, but urged them to “direct your anger and frustration at the Government and railway employers during this latest phase of action.”
“Working people across our class need a pay rise and we are determined to win that for our members in RMT,” he said.