The RMT is at odds with management over job cuts
Network Rail maintenance workers have voted in favour of strikes, bringing about the possibility of action over Easter.
The Rail Maritime and Transport (RMT) union said 65% of members voted. Of those, 77% backed industrial action.
The ballot was called over plans to cut up to 1,500 maintenance jobs and change working practices.
The union said it would remain available to talk to Network Rail to avert the strikes.
"Nobody should be under any illusions about just how determined RMT members are to win this dispute and to stop this reckless gamble with rail safety," said RMT general secretary Bob Crow.
Network Rail defended its proposals as modernising the country's railways.
"The way the railway is maintained and operated needs to change," the rail operator said.
"Work practices that date back to the steam age should no longer have a place on a modern railway. We cannot allow the unions to hold this country to ransom."