A protester dressed up as a chicken wearing a mask of the Transport Secretary as part of a demonstration outside a conference he had been due to address.
The Rail, Maritime and Transport union (RMT) accused Chris Grayling of "chickening out" of attending a Northern Transport Summit in Manchester on Monday.
The union is embroiled in disputes with five train operators over the role of guards on trains, which have sparked a series of strikes over the past two years.
RMT general secretary Mick Cash said: "Chris Grayling is running scared. He's scared of the passengers he's hung out to dry and he's scared of the staff whose safety-critical jobs his franchise shambles have left facing the axe.
"Chris Grayling may have chickened out of meeting RMT members and their supporters but I've got a message for him - you can run but you can't hide."
A Transport Department spokesman said: "The Secretary of State is not attending the summit as he is in London for the National Policy Statement in Parliament, a hugely significant vote that will benefit the whole country, including the North West. We recognise the importance of this event, which is why Transport Minister Baroness Sugg will therefore be attending."
RMT members on Arriva Rail North (Northern) staged three 24-hour strikes last week and further action has not been ruled out.
The union believes the Department for Transport is behind the controversial plans to change the role of guards, claiming that the policy has "failed" as workers continue to take industrial action, backed by many passengers and politicians.
Mr Cash said: "At the moment every Northern train has a safety trained, operationally qualified guard on board but if plans go through almost half a million trains a year across the north will be running around without a guard.
"At a time of increasing anti-social behaviour and recorded crime on trains it seems crazy that anyone would want to de-staff the trains or de-skill the staff currently on board but that's exactly what the Government and Northern are planning to do.
"Guards also assist people with disabilities and mobility impairments to access trains."