Transport union leaders attending today's annual meeting of Network Rail (NR) warned that they would oppose train service cuts and big bonuses for NR bosses.
The TSSA union urged those at the meeting in Manchester to vote against the award of six-figure bonuses for NR top directors including £641,000 for the company's chief executive Iain Coucher.
The RMT union said it would fight job losses and service reductions as well as any attempt to get rid of NR.
NR, which replaced Railtrack in 2002, has no shareholders but has around 100 "members", including members of the public, who hold the company's board to account.
The members will today be asked to approve NR bonuses which were announced last month.
Transport Secretary Philip Hammond was among those who urged NR to show restraint when it came to awarding bonuses this year, after the Office of Rail Regulation had said the company's performance had been "mixed".
Mr Hammond wrote to NR chairman Rick Haythornthwaite saying top NR directors were already "handsomely rewarded in terms of annual salary" and he spoke of the "potential for damage to the company's reputation" should big bonuses be paid.
But top directors were awarded bonuses totalling more than £2.25 million.
The new Government is considering changes to NR and today TSSA leader Gerry Doherty said Mr Haythornthwaite had effectively told public members, in a letter, that if they voted for the bonuses the board would fight for their existence in a restructured company.
Mr Doherty said: "This letter is a crude attempt at emotional blackmail in defence of the indefensible."
"The members should treat this letter with the contempt it deserves. They should put the country first and throw these bonuses out. They cannot be justified on economic or moral grounds. It is time to halt this gravy train."
RMT general secretary Bob Crow said: "The NR annual general meeting assembles at a time of great danger for the railways in this country. If reductions on the scale being projected are forced on the transport budget we have no doubt that it will mean thousands of job losses and catastrophic cuts to rail infrastructure and operations with lethal consequences.
"RMT will continue to mobilise to fight those cuts."
He said any attempt to sell off NR would mean "a nightmare return to Railtrack mark two - a model of rail operation that was a major factor in the Hatfield and Potters Bar (rail) disasters".
Mr Crow continued: "Passengers are already being told that they face fare increases of up to 10% this year. With carriage replacements scrapped, and cuts to maintenance and renewals already the order of the day, it is clear that the Government plans to force passengers to pay through the nose to travel on overcrowded and condemned trains running on creaking and poorly-maintained track."Reuse content