Around 30 members of the Ticket 2 Ride group tried to board a train from Doncaster to King's Cross yesterday morning, but some could not be accommodated.
Paralympian Jenny Ridley was only able to sit in the smoking section of the train while others could not get on at all.
Jesse Harris, a spokesman for the group, said that it was time action was taken to end the discrimination against millions of people with disabilities who need to use the public transport system.
"Unfortunately, people like Jenny Ridley have to put up with a lot of things like that – usually there are just two spaces for wheelchairs on a train.
"For many of us, rail travel remains a completely impractical, if not impossible, means of transport. Disabled people attempting to travel by train have to book up to 48 hours in advance – sometimes only to find that standing passengers are occupying the wheelchair space.
"In 2002, the Government revealed that there wasn't a single UK station which met Strategic Rail Authority (SRA) design standards, and we've got to wait at least another 15 years before trains are forced to get their act in to gear.
"It is time for the rail industry and its regulators to take responsibility for this shameful situation and put an end to social exclusion on the trains."
More than 100 campaigners travelled from Doncaster, Cardiff and Plymouth to stage a protest at King's Cross station.
They want a four-point action plan to be implemented, which calls for the SRA to carry out an immediate audit to assess the scale and impact of the disability access problem.
They also want Government to give priority to the Disability Discrimination Bill, and for train and station operators to do more.
Campaigners say 40 per cent of UK mainline stations are not staffed, and 235 out of the 275 London Underground stations require the use of stairs or escalators.
The SRA was not available to comment last night.