Its legal advisers recommended action against Nicholas Van Hoogstraten, who has built a barn and barriers to prevent access to the path, on his land in East Sussex. Mr Van Hoogstraten has pledged not to give in to the "disgusting" ramblers. The blocked footpath runs for half a mile through his High Cross estate in the heart of Sussex downland near Uckfield where he is building a vast mausoleum for his remains and a gallery for his art collection. The buildings form part of Hamilton Place, said to be the most expensive private home built in Britain this century.
Ramblers said Mr Van Hoogstraten had erected a barrier with a sign warning: "Private Property - Keep Out". Old refrigeration units now block their path. The association also claims East Sussex County Council, responsible for keeping highways and footpaths open, has been dragging its heels on the issue. The council agrees it is a public footpath, but says budget constraints prevented it from taking action.
A Ramblers' Association spokesman said: "We have decided to take this course on behalf of the public who expect to be able to use public rights of way, without fear of being abused, threatened or hindered by a selfish and arrogant bully like Mr Van Hoogstraten.
"There are many mean-spirited landowners like Mr Van Hoogstraten who illegally block footpaths. So we feel it's vital that we take a stand on this.
"Almost a quarter of Britain's priceless network of rights of way is blocked or impassable. This is largely because local authorities are reluctant to take law-breaking landowners to task. This situation must not be allowed to continue otherwise more and more landowners, like Mr Van Hoogstraten, will think they are above the law."
Mr Van Hoogstraten, 53, who also has homes in Cannes, Monte Carlo, Maryland and Florida, yesterday suggested armed security guards might be posted at his estate, though it was not clear whether he was suggesting that he or the Ramblers' Association would have to do that. He said on the BBC Radio 4 Today programme: "It is not a public footpath. It never has been. Nobody has ever given me any legal evidence that it was a public footpath."
The path was closed long ago, he said. "This issue was dead 12 to 15 years ago. It has been brought up for political reasons because of other government nonsense about a right to roam."
He said the route was shown as a "path unmarked" on various maps, which was different from being a public footpath.
"I'm not having anybody on my land in any event. They will never get away with it. I have been picked on by these disgusting people who have nothing better to do. I know these types. They are people who don't have any stake in society. They're not walking in the countryside. They are hell-bent on trespassing on private property. I'm very happy for people to walk in the countryside. I'm not happy for people to be walking on other people's private land."
He denied dealing "viciously" with the walkers. But he said the Ramblers' Association "can waste their time because ultimately, what they will need to do is have some kind of armed security guards there 365 days a year".
He added: "I'm not threatening these people. It's just that there may be an occasional incident, somebody may get through as a trespasser without us knowing about it. But ultimately, this will never become a public footpath."
Mr Van Hoogstraten expects work at Hamilton Palace to take several years at a final cost of pounds 30m. It will include a mausoleum and 600ft gallery for his art collection, with one of the few Holbeins still in private hands, possibly two Turners, and an extensive collection of French antique furniture, with a pounds 1.5m cabinet.
The mausoleum, designed to last 5,000 years, resembles mortuary temples built by the pharaohs, with massive walls and foot-thick concrete floors. He has pledged to keep the public out even after his death when it is to be sealed forever.
He said: "There won't be any riff-raff coming in, standing on the Persian carpets. The only purpose in creating wealth like mine is to separate oneself from the riff-raff."
Mr Van Hoogstraten, the son of a shipping agent, sold a stamp collection as a teenager which gave him capital to start his property empire. He bought his first property in the Bahamas and the business mushroomed. He went on to buy property in the Notting Hill area of London and in Brighton and Hove in East Sussex and won a reputation as a ruthless landlord. He featured in a World In Action documentary describing tenant harassment.
By 22, Mr Van Hoogstraten was described as Britain's youngest millionaire, with 350 properties in Sussex alone. He is understood to own many properties in London. He has five children by three wives.
In the 1960s he was jailed for four years for aiding a hand-grenade attack on the home of a synagogue official in Brighton. The judge called him a "sort of self-imagined devil who thinks he is an emissary of Beelzebub".