Train staff in the North East will be among those who have voted to take industrial action.
Workers on Northern Rail, which runs services across the North West, North East and Yorkshire, have voted to go on strike in a row over jobs and safety.
The union is committed to ending the two-tier workforce that the security contract creates and calls for all workers to be brought in-house on decent pay and conditions.RMT general secretary Mick Cash
Members of the Rail, Maritime and Transport union backed walkouts by 80% and other forms of industrial action by 90%.
Northern Rail, which runs trains from Sunderland, Seaham and Hartlepool, has said the dates of the strike are still to be established.
It will then be able to tell customers what service will be affected.
The union said it is in dispute over a series of issues, including the removal of permanent posts and the creation of zero-hour jobs via a contract with a security company, cuts to booking offices and attacks on the role and responsibility of train guards.
The union said Northern Rail had also given no commitment that there will be no compulsory redundancies beyond the end of its current franchise in February 2016.
RMT general secretary Mick Cash said: “RMT has made every effort to win assurances from Northern Rail over jobs, services and safety.
“However, the company continues to ride roughshod over our efforts.
“We therefore had no option but to ballot all staff for action to force the company to take these issues seriously and the members have now voted decisively for action.
“That mandate will now be considered by the union.
“The union is committed to ending the two-tier workforce that the security contract creates and calls for all workers to be brought in-house on decent pay and conditions.
“We are also committed to keeping ticket offices opening and defending guards’ jobs, which are safety-critical.
“The RMT remains available for talks and we expect the company to now take this dispute, and the issues at the heart of it, seriously.”
Northern Rail is owned by a 50:50 joint venture between Serco Group and Abellio, a subsidiary of NS Dutch Railways. The company employs 4,900 workers and runs 2,500 services every week day.
The RMT said 1,500 of its members are involved in the dispute.