The historic home of Sir Walter Scott in the Borders has been set a £10m target in order to survive.
By Giancarlo Rinaldi
BBC Scotland news website
South of Scotland reporter
Failure to raise the sum could see Abbotsford House - near Melrose - close to visitors within four to five years.
Executors of the estate of Dame Jean Maxwell-Scott, the National Trust and Faculty of Advocates, have drawn up a strategy to raise the funds.
Half the money would be used to improve facilities, with the rest put in an endowment fund to cover trading losses.
Abbotsford administrator Jacquie Wright said the loss of the house - where Scott wrote the Waverley novels - would hit the area hard.
"It is a major visitor attraction in the Borders without a doubt," she said. "He was the world's first best-selling author.
One of the rooms inside Abbotsford which visitors can see
"In the UK, sad to say, he is not fashionable but he is still fashionable in Russia, the Baltic countries and United States.
"We get around 31,000 to 35,000 visitors a year and 35% to 40% of them are foreign.
"It's a sort of place of pilgrimage for many people."
Ms Wright has ambitious plans to boost the house as an attraction, currently open from March until October, and continue the good work done in preserving it by Patricia and Jean Maxwell-Scott.
Without the £10m funding package required, however, Ms Wright said the house could be living on borrowed time.
"It is difficult to say how long it will last," she said.
"There is an annual deficit because most of these houses have an annual deficit - it might be four or five years."
Executors of the estate of the last family member to live in the house, Dame Jean Maxwell-Scott, have also expressed concerns that plans for housing nearby could hamper their fund-raising.
They have written to Scottish Borders Council objecting to the inclusion of plans for housing nearby in its finalised local plans.
Walter Scott selected works
The Lady of the Lake (1810)
Rob Roy (1817)
The Heart of Midlothian (1818)
They say that it could put off potential donors to the £10m target.
The council's development control manager Alistair Lorimer confirmed that a continued application for about 70 houses opposite Abbotsford was expected to come up for consideration later this year.
He added that this could be decided before the public inquiry into their local plan because of supplementary guidance on housing developments.
The authority has previously stated that the preservation of trees and new planting could minimise any adverse effects on Abbotsford.