On buses and trains It's a question that has sparked a four year legal battle after a woman with a baby refused to move out of the way on a bus in Yorkshire. Most firms prefer to ask able-bodied travellers to move, rather than make then, but Supreme Court judges will today decide if that policy goes far enough. Our legal affairs correspondent Clive Coleman has this report. Doug Paulley arriving at the Supreme Court for the culmination of a four year legal battle that started simply because he wanted to get on a bus. In 2012, he tried to board one from Wetherby to Leeds, but a woman with a child's buggy was in the wheelchair space and refused the driver's request to move. Doug couldn't travel. I appreciate it's difficult with kids and luggage, and everything else, to fold a pushchair or to move it, but ultimately unless she did that, you know, she's effectively stopping me from be able to use that bus. He sued the company First Group, and won a ruling that its policy of requesting, but not requiring, able-bodied people to move from the wheelchair space was unlawful discrimination. But that was reversed on appeal. It's an issue everyone has a view on. You're already sat there, where can you put a pushchair I wouldn't do that, but I can see why people would. Our worst enemies are the drivers who actually don't try to enforce the priority space. Well it happened to me twice last week, that a driver just pulled away from the stop, because there was a buggy on board, without even trying to speak to me. And now this battle between the wheelchair and the buggy has arrived here, at the highest court in the land, where seven justices will decide whether bus companies need simply ask mums and others to move from the disabled space, or make them move. This morning, lawyers for Mr Paulley underlined the value of being able to travel. There's a lovely quote from Seneca, that says "Travel and change of place impart new vigour to the mind." If you can't travel, or you're put off travelling, you become isolated. But First Group stands by its policy. Our drivers will ask a passenger in the strongest, politest way they can, as we train them to do so. When somebody does refuse to move, it's extremely unfortunate. We do believe that the process we take is the most feasible. A win for Doug Paulley could mean that wheelchair users have certainty that if there's an able-bodied person in the wheelchair space, they will be made to move. Clive Coleman, BBC News.