Network Rail was today (April 1) taking the RMT union to the High Court in an attempt to stop next week's four day national rail strike.
The company, which runs the UK rail system, is to ask a judge to declare the union's ballot of maintenance workers and signallers illegal.
The strike is due to start next Tuesday, April 6.
If it goes ahead, it will be the first national rail stoppage since 1994.
It said the ballot had won only a majority of 112 among its 5,800 signaller members.
But it said it had found "scores of inaccuracies and discrepancies affecting around 300 votes or potential votes found in the ballot."
Network Rail said this because of this "we felt we had to go to strike."
The hearing is being held in the High Court in London this morning and the result is expected around lunchtime today.
British Airways successfully won a similar injunction last December to stop its cabin crew striking over Christmas.
Bob Crow, the RMT's general secretary, described the hearing as a "scandalous attempt" to stop workers exercising their right to strike.
He was quoted as adding: "RMT is putting together an experienced legal team, including some of the most high-profile employment law experts in the country, and we will be mounting the most robust defence possible in the high court against this attack by Network Rail on our internal democracy."
Network Rail said the irregularities in the ballot included: balloting 11 signal boxes that closed years ago; details of more votes than employees in 67 places; failing to ballot 26 workplaces with 100 employees and balloting staff who were ineligible to vote.
Network Rail said: "The impact of the strike on millions of people and the affect it would have on Britain's economy is simply too serious to leave to the hope that further talks would be successful.
"We still believe that a negotiated settlement is the way to resolve the dispute and we hope that the unions will rejoin us at the table."
Talks to settle the dispute, which also involves the Transport Salaried Staffs' Association (TSSA), failed earlier this week at the offices of the UK arbitration service ACAS.
The dispute is over Network Rail's plans to cut 1,500 jobs which the unions say will jeopardize passenger safety.
Network Rail, which has rejected this claim, said it wants to achieve the job losses through voluntary redundancies.
www.networkrail.co.uk www.rmt.org.uk www.tssa.org.uk