The Government is not expected to intervene to buy the contents of Lissadell House, which are due to be auctioned tomorrow.
In an attempt to keep the contents in the house, its new owners have suggested three alternative proposals to the Minister for Finance, including the introduction of a special tax-relief scheme if they bought the contents personally.
The proposals were contained in a letter from Ms Constance Cassidy SC and Mr Eddie Walsh SC to Mr McCreevy last week.
They bought the house in August for a reported €3.5 million from Sir Josslyn Gore-Booth, nephew of Countess Markievicz, who grew up there. The Co Sligo house also has associations with the poet W. B. Yeats.
The couple intend to keep the house open to the public and see the contents as being essential to maintaining its historic character.
The contents are to be sold tomorrow at auction by Christies on behalf of Sir Josslyn.
Yesterday, more than 300 people visited Lissadell, where the auction is taking place, to view the 628 lots.
Sir Josslyn has already refused an offer of 750,000 for the contents from Ms Cassidy and Mr Walsh and is seeking 250 per cent of the highest valuation of any lot they wish to buy to prevent it from being auctioned off.
Ms Cassidy told The Irish Times it "made no economic sense" to do that.
They have however secured the gasoliers and organ for an undisclosed sum. This followed a threat of a High Court injunction by An Taisce to prevent their sale at auction.
The two barristers wrote to Mr McCreevy outlining three proposals. One was the State purchasing all of the remaining lots and leasing them back to the couple. The second option was to do a "euro for euro" deal where the State funded half the purchase costs, with Ms Cassidy and Mr Walsh funding the remainder.
The final option was for Mr McCreevy to introduce a tax-relief scheme to where they could claim the costs of purchase against their tax bills.
However, according to Government sources last night, the Department of the Environment had received expert advice that all the items of historical importance in relation to Countess Markievicz had already been sold.
"It's highly unlikely that the State will be intervening to buy the contents," according to the source. "The issue of tax relief is a matter for the Minister for Finance and he alone will decide on that one."
The State had refused to buy the house on the basis that refurbishment costs and transforming it into a public access building could exceed €30 million.
As of last night, the couple had received no response from any Government department, which Mr Walsh "found strange".
Ms Cassidy said: "We could have just bought Lissadell for a shell, but we have decided not to do that.
We don't have to buy the contents, they are of no benefit to us personally."