The agency handling the sale, Knight Frank & Rutley, said: 'No contracts have been signed and potential buyers are not being deterred from viewing; it is now a race to complete contracts and there is considerable interest in all or part of the estate.'
The property on offer is Tremlett Hall Farm, which surrounds the hamlet of Greenham on the Somerset-Devon border. As well as the farmhouse there is a bungalow and a staff cottage in the village. The buildings are considered exceptional for a farm of its size.
Part of the land lies close to the walls of Sir Edward's 15th-century home, Cothay Manor.
Martin Lamb, at the agents' office in Exeter, said: 'We had a lot of interest and we wrote asking for best offers to be made. We accepted one of those bids, but it will be nine days on Sunday since the deadline for exchanging contracts.'
Lady du Cann, however, speaking from Cothay Manor, said that lawyers were still negotiating the du Canns' purchase of Tremlett Hall Farm and its estate. The farm is still occupied by tenants, who will leave when the sale is completed. My husband had sold some land and has been let down with the payment. We are still expecting it to come. We have bid the most money and have the contracts organised.'
Since the Leeds Permanent Building Society repossessed the property, agents acting for the society have become increasingly annoyed. Attempts to secure possessions at Tremlett Hall Farm were thwarted when estate workers prevented entry. Their blockade was lifted only after the threat of an injunction. But then a lorry mysteriously broke down across the farm entrance.
When bids were sought for the three-bedroom farmhouse and its 308 acres, there were 13 replies. Then a 14th - from Sir Edward, backed by Abbey National - arrived at 4.45pm on deadline day.
Sir Edward's bid was in the region of pounds 600,000, and as it was the highest it had to be accepted. But Sir Edward has failed to exchange contracts.
A local farm manager said: 'We have been surprised there has not been more publicity about the affair. It has been going on since June.'
He said the man who was MP for Taunton for 30 years until 1987 still commanded respect in the surrounding villages and among his farm staff. 'He is respected for his ability to have no respect for money whatsoever.'
Sir Edward's business dealings have frequently overshadowed his political career. As a rising star in the Conservative Party he was once tipped as a possible leader. He backed Margaret Thatcher in 1975 and is a former chairman of the backbench 1922 Committee.
Lady du Cann confirmed that the Leeds Permanent was not the first building society with which Sir Edward had been embroiled in disputes over non-payment of debts.
In 1986, Eagle Star Insurance started legal proceedings over repayment of part of the mortgage on the Cothay Manor estate. A fortnight later the Halifax Building Society took legal action for repossession, which was settled before it went to court.
There have been other clashes with creditors. Twice, in 1984 and 1985, a summons for unpaid water rates was taken out against Sir Edward by Wessex Water Authority in Bristol county court. In 1984 a consulting engineer issued a writ against him over non-payment of fees for advice about quarrying silicon on the estate.
Sir Edward's bad debts were even aired in the House of Commons. In April 1989, Dale Campbell-Savours, the Labour MP for Workington, tabled an Early Day Motion asking the House to note a summons against Sir Edward by a London firm of lawyers, Boodle Hatfield.
The motion said that clients of Boodle Hatfield had received a cheque for pounds 25,000 from Sir Edward which had bounced. The debt was later settled.
Lady du Cann said the publicity surrounding the debts was obscuring the great deal of good work her husband had done - 'This whole thing is becoming absurd. Look in Who's Who and see what he has achieved. There is masses of it.'
She felt that difficulties over debts were a normal part of business life. 'If you are in business then you are going to have arguments with people,' she said. 'An awful lot of what is published is wrong, but he ignores it.
'We have had difficulties with Tremlett Farm because somebody has been foul with us and not paid up. There is a knock-on effect. My husband is a private person. He is not an MP or the chairman of any company and he has retired. He is nearly 70 and I really think enough is enough.'