Network Rail has sparked anger by refusing to award annual bonuses to staff who went on strike in a long-running dispute.
The decision could affect up to 20,000 members of the RMT union, whose members took industrial action over pay, jobs and working conditions.
The dispute was settled in March when they voted to accept a 9% pay rise.
However, those who took part in strikes from June 2022 onwards will not receive a bonus worth about £300.
A spokesperson for Network Rail, which owns and maintains thousands of miles of railway across Britain, told the BBC that it had been "crystal clear" with trade unions and employees about the fact that strike action would affect its performance-related bonus scheme.
"Our position was made very clear - any discretionary payments would focus on those who continued to support rail services during industrial action," they added.
Previous bonuses
In the past, bonuses for eligible Network Rail staff have reached about £1,000.
Due to industrial action affecting the company's performance, the award is expected to stand at about £300 this year.
The move prompted anger from the RMT union, which represents thousands of signal workers and maintenance staff who work for Network Rail.
Its general secretary, Mick Lynch, described the decision as "disgraceful".
He suggested that Network Rail was penalising members for participating in trade-union activities and slammed it as "a transparent attempt to divide the workforce".
Nearly 13,000 people have signed a petition on online platform Organise calling on Network Rail to give a bonus to all of its workers.