Six “fat controllers” have gathered outside a meeting of rail bosses to protest against “astronomical salaries” and “futile” bonuses paid to publicly-funded directors.
Network Rail, which manages UK rail infrastructure including track and stations, is holding its annual general meeting in Glasgow today.
Members of the Transport Salaried Staffs' Association (TSSA) union dressed as so-called fat controllers waved placards attacking the Network Rail "gravy train" and its "great train robber" directors.
TSSA senior regional organiser Tom Kennedy said: "We are protesting at the £18.5 million bonuses that Network Rail are proposing to pay to themselves over the next three years.
"Network Rail is publicly-funded. It gets £4 billion every year from the UK taxpayers, and the six senior directors of the company are all on salaries of between £330,000 and £500,000.
"They get a bonus each year of between 30% and 60% on top of their salaries, a long-term bonus that they get over three years and also golden handcuff arrangements.
"The UK taxpayer is funding astronomical salaries for people who are just doing their job."
He said the remuneration committee which sets the salaries operates "under a cloud".
"It's a gravy train and there's no transparency whatsoever," he added.
"The Government is giving £4 billion of taxpayers money to this small group of directors, and at the same time are cutting back on benefits and penalising pensioners and the disabled in the tax system."
He added: "The McNulty Report said that the UK railways are 40% dearer than their European comparators.
"We are paying the most expensive fares in Europe, but all the money comes out of the same pot at the end of the day."
He said if Network Rail were not paying "unnecessary and futile" bonuses the money could be diverted to operators to bring down fares, or could be used to improve the rail infrastructure.
"The chair of the remunerations committee once said: we've got to be careful or we'll lose these people," said Mr Kennedy.
"But that is a specious argument. Network Rail has got about 38,000 employees, and if one of these directors stepped out of the way there would be any number of capable people willing to take their place at half the price."
A Network Rail spokesman said: "The executive directors of Network Rail waived their annual bonuses this year, and currently there are no bonus arrangements in place.
"Nothing is being voted on today in relation to the annual bonus or the long-term bonus. That is still in discussion with the ORR (Office of Rail Regulation) and the Government, and we don't expect any resolution until the autumn.
"Network Rail is the biggest civil engineering company in the country. It's investing £12 billion to 2014, and is responsible for getting four million people safely to their work every day.
"It's an extremely complex business, and you want the best people to keep the country moving."