Nevertheless, the decision to let Grayling go to Qatar rather than keep him in the United Kingdom to fight the government's corner is being seen by many Westminster watchers as a clear vote of no confidence in the transport secretary.
"We are investing in the biggest modernisation of our railways since the Victorian times", a spokesman added.
"Our members are protesting today to say it is time to cut our fares not our staff and for a publicly-owned railway where every penny of passenger revenue goes to improving services". How much has your rail fare increased by?
"But ultimately the government need to take our railways back into public hands".
"We understand how passengers feel when rail fares are increased".
Mr Grayling also needs to remember that many passengers have to use the train - they have no alternative means of transport - and that the pace of change in the North is far too slow.
Train tickets have been sent soaring today - in the biggest price increase in five years.
General Secretary Frances O'Grady said: "Another year, another price increase".
Fury as West Norfolk rail passengers feel pinch from fare hike
Keolis separately operates the TransPennine Express alongside First Group and the Docklands Light Railway, alongside Amey, which is a subsidiary of Spain's Ferrovial.
"But it's also because passengers pay for the bulk of the running costs, despite the obvious economic and social benefits to the whole country from having a well-used rail network".
South Western, which runs services into Britain's busiest station, Waterloo, said the union was "scaremongering" and that guards would be retained.
"It should become absolutely standard for all trains on the British railway network to have seamless connectivity, as it's essential for attracting the smartphone connected generation to rail, as well as the business traveller working on the move", he stated.
But Shadow Transport Minister Andy McDonald said increasing rail fares is a "counterproductive move" and there is a "real danger" it could force more people into commuting by auto.
Meanwhile in France, the latest figures released by the Campaign for Better Transport (CBT) show the annual cost of the commute from Ballancourt-sur-Essonne to Paris is just £750. "The answer to this racket is a full return to public ownership of Britain's railways and an end to this gross profiteering". Trains in London and south-east England are typically 18 years old, while those on regional services are 24 years old.
The 3.4% raise, announced previous year, has prompted anger from unions and the Opposition, which described the hike as "staggering" and argued the government was making rail travel unaffordable for many people.