It has asked the TSSA rail union to withdraw notice of industrial action, saying there are “numerous defects” in its ballot.
The move came just before talks were due to resume on averting a strike by thousands of workers over pay.
The TSSA union, which represents white-collar staff, said its members voted strongly in favour of industrial action.
Network Rail (NR) said in a statement, “We have asked the TSSA to withdraw notice of their industrial action as we believe there are numerous defects in their ballot information.”
Members of the Rail, Maritime and Transport (RMT) union are also planning to strike, warning that train services will be at a standstill next Tuesday if the 24-hour walkout goes ahead from 5pm on Monday (May 25).
Talks were held for six hours at the conciliation service Acas yesterday and are due to resume later today (May 20).
Manuel Cortes, leader of the TSSA, said, “We are frankly puzzled as to why NR are taking this legal route whilst talks continue today at Acas to solve this dispute and avert next week’s strike action.
“They seem more determined to impress (Transport Secretary) Patrick McLoughlin and the Tories than making a serious attempt to resolve this pay row and ensure that the trains run on time over the bank holiday.
“We want to settle this around the negotiating table, not in the High Court.”
Talks between Network Rail and the trade unions aimed at resolving the ongoing rail dispute resumed for a third day today at conciliation service ACAS.
Mark Carne, Network Rail chief executive, said, “We are continuing to talk with the unions and we believe there is a settlement to be had. I sincerely hope we can reach one and my team will be available all week, and into the weekend if necessary, to find a deal to prevent strike action.
“From the very start of negotiations we made clear that we want to reward our staff for the incredible job they do – but that any pay rise needs to be linked to smarter, more effective ways of working.
“We can’t bank on the unions calling off the strike, so we are now concluding our contingency plans so passengers can make decisions about their journeys.
“If the strike goes ahead, it’s important that people check before travelling and are aware of the special measures put in place by train operators for people who have already booked tickets.”
Industrial action to affect National Rail services
Members of the RMT & TSSA Unions, who work for track and infrastructure operator Network Rail are planning to take industrial action on Monday (May 25) and Tuesday (May 26).
Planned engineering works/service changes for Monday are listed here