Lord Smith of Finsbury, the president of the Ramblers Association, has attacked the court decision to limit access to the countryside near Ann Gloag's home, and called for the decision to be overturned.

Chris Smith, a former cabinet minister and an experienced climber and hill walker, has thrown his weight behind a campaign to reverse the entrepreneur's successful attempt to stop walkers entering parts of her 23-acre estate near Kinfauns in Perthshire.

Mr Smith said: "It's not as if this is just about personal privacy and keeping prying eyes away from your windows.

"If that was all, it would be understandable. But this is about keeping people hundreds of yards away from anywhere near the castle.

"Much of the land Mrs Gloag wants to fence off can't even be seen from the castle itself. This is more about privilege than it is about privacy."

Mr Smith condemned the decision made by Sheriff Michael Fletcher on June 12.

Speaking to The Herald, he argued: "It is a judgment that many people believe is deeply flawed, and it runs counter to the whole intention of the Scottish Land Reform Act.

"Even more disturbing is the reason Sheriff Fletcher gave for his decision. He said that it was because Mrs Gloag was wealthy and had a high profile that she was entitled to a higher degree of protection. This sounds to me very like one law for the rich and another for the poor; this cannot be right."

Mrs Gloag, who along with her brother Brian founded the Stagecoach bus company, is worth an estimated £395m.

She lodged the application for a perimeter fence at Perth Sheriff Court last year, arguing that she wanted to protect her privacy and enjoy her home.

Mr Smith believes the decision will undermine access to land throughout Scotland.

"This case as it stands threatens the whole future of walking and rambling in Scotland.

"Getting it reviewed by the courts, or if necessary getting the law amended to make sure it can't happen again, ought to be a priority.

"And perhaps at some stage in the future we'll have the chance once again to wander through the native Scottish woodlands round the corner from Kinfauns Castle - a place that can be cherished by future generations of walkers, and not just enjoyed by a single person," he maintained.

The court proceedings centred on a 7ft perimeter fence, topped with barbed wire, which was erected around part of the 23-acre estate without planning permission.

Retrospective permission was granted by Perth and Kinross Council, but the local authority and the Ramblers Association wanted a stretch of the one-mile fence moved.

After visiting the castle, for which Ms Gloag paid £4m in 2005, Sheriff Fletcher ruled that the fenced area in question was not land which could be accessed under the terms of the Land Reform (Scotland) Act 2003.

Instead, it fell under Section six of the act - land which was exempt for reasons of privacy or enjoyment by the owner.

Sheriff Fletcher, implicitly criticising the law, said the provisions were extremely general and not helpful.

His judgment continues: "The house is of a substantial size, being one of the larger country mansion houses in Perthshire and indeed probably in Scotland. It is of a very substantial value such that only a small number of persons would be able to afford to own it and run it as a private house."

Expert in Scots law believe the case could go all the way to the House of Lords via the Court of Session.