I am looking to build a case to see if there is any scope for a case to be brought against a train operating company that is now making excessive profits from car parking. Any advice on a deent group / lawyer who would be interested in this ?
In a word, no.
In a few more words, the car park is a private enterprise. As such, they can charge as much as they want, and if people are paying it they're going to make money. You are not forced to park your car there (and before you say that you are because of work/childcare/other excuse, you are not
forced to park your car there by the literal interpretation of the word forced). The TOC involved is not going to fall foul of any legislation by charging high prices for its car park. If you, and presumably other people, use the car park and pay them these "Exceessive" (sic) fees, they will assume that you're quite happy to pay for it.
You have made an interesting claim that the train operating company is "...now making excessive profits" from the car parking charges. I would assume, therefore, that you have evidence to back this up if you are taking them to court? Profit, of course, is not the same as turnover. The turnover will be high if usage and fees are high, but that does not necessarily equate to high profits. If the running costs of the car park are high for whatever reason, that may mean that the company is not making a huge profit on car parking. To take that claim to court, you're going to need evidence in the form of cold hard numbers, which I'm sure you won't have.
Lowering parking charges can be a mixed blessing. Whilst it makes your journey cheaper, it also encourages people to use the park and ride and if space is at a premium (which it does tend to be in station car parks in my experience), you often end up in a situation where supply0 outstrips demand, and then you'll be moaning that you can't get parked at your local station any more!
No good lawyer will waste their time on this case, because there is no case.
--- old post above --- --- new post below ---
Some sensible advice: if you're travelling by train, leave the car at home
As many people have already pointed out, quite a lot of people in this country do not have public transport on their doorstep. For some people, the car is by far the best option to get to the station, and I don't think it's necessarily inappropriate for people to use park and ride facilities.
Cycling depends on ability, confidence and to an extent the actual road/path taken. Walking is not always possible/practical over longer distances. Taxis can be unreliable, particularly if you're somewhere rural.
Of course, there are plenty of people who drive quarter of a mile to the railway station, and that's just silly. But if your nearest station is ten miles away, driving to it seems perfectly reasonable IMO.