Wales's disability rights commissioner is taking legal advice on whether the absence of a lift at a rail station's £5.5m new platform breaks the law.
The £5.5m new platform has no lift for people with mobility problems
Network Rail is paying cabbies £3 to ferry passengers with mobility problems from other parts of Newport station to platform four.
It says a lift will be in place by 2010 when the city hosts the Ryder Cup.
But commissioner Kevin Fitzpatrick said the needs of ordinary customers, rather than golfers, should come first.
Passengers using the new 270m (885ft) platform, which is on the main line between south Wales and London Paddington, must climb a footbridge or walk the half-mile (0.8km) through the railway station's car park.
Critics say the route is too difficult for disabled or elderly people or passengers with pushchairs.
The Disability Rights Commission had said earlier that while the situation was not ideal, Network Rail may be within the law as it is providing access via the taxis.
Kevin Fitzpatrick said passengers seemed to be treated "second class"
However, Dr Fitzpatrick is now seeking legal opinion on whether the platform, as a new development, is breaking disability discrimination laws.
"What's driving this is the needs of golfers, not the needs of ordinary customers," he said.
He added: "Throughout Wales there are lots and lots of people who'd travel by train if they could.
"It certainly ignores them and excludes them and means that they are second class in terms of any provision that the station is going to be able to give to them."
Network Rail has said that building a lift now will cause disruption, but there will be one in another redevelopment when the city hosts golf's 2010 Ryder Cup.
When the problem first emerged a Network Rail spokeswoman said: "The taxi service is there as and when needed and can be accessed via a help-point on the platform.
"Lifts will be put in a new station development by the time of the Ryder Cup in 2010.
"To do so now would require a lot of development work and we did not want to delay the extension."