The future of one of the grandest houses in Holcombe hangs in the balance after a long-running disagreement between the brothers who inherited the 18th century mansion from their mother seven years ago.

Higher House on Moor Road was first advertised for sale at £675,000 in 2010, two years after the death of Mrs Margaret (Peggy) Haes.

The estate agent who advertised the house says a lengthy dispute about its future has prevented at least three prospective buyers from proceeding.

Neighbour John Ireland, local historian and secretary of the Holcombe Society, said: "We have a serious problem on our hands. This is one of the most important houses in Holcombe. The building is in danger.

"It is in the centre of our conservation area and has been the scene of important events for nearly 300 years. Prime minister Stanley Baldwin and Lord Derby stayed there."

In 1967, Peggy Haes opened a pioneering riding school on the hillside above Higher House where volunteers taught disabled and disadvantaged children to ride on a string of horses and ponies.

Princess Anne supported Peggy’s ‘pony riding for the disabled’ movement and in Peggy’s honour the school has been re-named as The Margaret Haes Riding Centre.

Mr Ireland said: "Peggy was a very grand lady and an expert horsewoman. As a member of the influential Whitehead family, she was given the house as a wedding present in 1934.

"Now it seems to have been abandoned to the winter weather as a result of an interminable series of problems. At least three people have tried to buy the house. They have all failed."

The house, with stables and nearby meadows was left to be divided between Mrs Haes's sons; John, 78, who lives in the village, and Robert, 73, who lives in Berlin. Both say they are keen to protect the future of the riding school, founded and registered as a charity by their mother.

Twelve ponies are stabled at the school for taking disabled youngsters on escorted rides over the moors and for teaching the art of riding to able-bodied enthusiasts.

John Haes said: "I would like my mother’s charity to be protected by having the stables and the riding school owned by a trust and sold separately from Higher House. But my brother does not yet agree."

Robert e-mailed the riding centre in May 2013: "I can quite understand that you are anxious for the future of the Riding Centre as it stands at present. The whole matter has been rather complicated, but the final touches are being put to a 20-year lease, which I understand will be discussed with your committee in the near future. Our family are also very interested that 'Mother’s Baby' continues to flourish for many years to come.

In an e-mail from Berlin, Robert Haes assured the charity committee: "So, the matter is in the hands of our executors and I am sure you will be satisfied with the outcome shortly."

But his brother, now president of the Margaret Haes Riding Centre, told Lancashire Magazine: "I am very worried about the situation. My brother and I were executors of the will, but my brother has given power of attorney to a local solicitor. The executors have not sold our old home and it lies unheated in mid-winter.

"There is a dispute about the arrangements for the sale of Higher House. I wish to preserve the long term security of the riding school and see no reason why Higher House cannot be sold separately from the riding school, according to my mother’s wishes.

Local estate agent Nick Hitchen said three potential buyers had faced contractual problems and the matter was now in the hands of the solicitors Latimer and Lee.

Stephen Latimer, senior partner of solicitors Latimer & Lee, said: "I am currently waiting to hear from Robert Haes who is the other beneficiary and lives abroad."