The boss of Network Rail has revealed he would accept a Christmas bonus of £135,000 despite overseeing the travel chaos after Boxing Day that left thousands of people stranded.
The train company has been fined £53.1m for the disruption by the Office of Rail Regulation, who said it fell "significantly short" of punctuality targets.
Thousands of commuters were stuck trying to get in and out of the capital on 26 and 27 December as King's Cross station was closed after engineering works were not completed on time, leading to overcrowding and closures at Finsbury Park.
But Mark Carne, in a defiant radio interview from his home in Cornwall, said the pay-out was "only" 20% of his basic salary and said there are "far more important things to talk about".
Carne said the figure could be reduced to 5% of his annual salary of £675,000 in light of the Christmas fiasco.
Sources close to the cabinet have disclosed that Transport Secretary Patrick McLoughlin is prepared to block any pay-out, The Telegraph reports.
McLoughlin said the pay-out must be "slashed", and sources say he is prepared to use legal powers to stop a six-figure deal.
Michael Dugher, the shadow transport secretary, said big bonuses would be "perverse and indefensible".
Under Network Rail's operating terms, remuneration packages for executives must be signed off by the transport secretary and the chief secretary to the Treasury.
Carne, the former vice-president of Royal Dutch Shell, proposed an industry-wide review into whether repair works should take place at Christmas.
At one point during the interview with BBC Radio 4's World at One, he simply fell silent as he was questioned over whether he would take the bonus pay-out.
"When I took this job on, the bonus potential of this role was 160% of my salary. One of the first things I did, was reduce that bonus potential to only 20% of the salary, which is a maximum of £135,000," he said.
Laughing, he added: "The maximum bonus I am likely to get will be about 5% of my salary, and a matter for the remuneration committee at the appropriate time."
Robin Gisby, another senior executive, had been in line for a £371,000 bonus, even though he will step down in the new year. However, in a dramatic change of plan, Network Rail claimed this morning he will not get the reward, based on performance from 2012 to 2015.
Asked whether Gisby was the "guilty man", Carne said: "Robin is our operations director, he leads the operations of the railway... I'm not going to prejudge the investigation."