A cash shortfall means a new museum celebrating the life and works of Robert Burns will not be ready in time for the 250th anniversary of his birth.
The Burns Museum will not be open for his 250th anniversary
Campaigners had hoped for a grand opening on 25 January, 2009, but the National Trust for Scotland (NTS) said it would not be ready.
It said it will be open either late next year or even early 2010.
The museum at Alloway near Ayr has been given £11.3m funding but more money needs to be raised.
John Skilling, the secretary of the Burns Monument Trust, the body which owns Burns Cottage, said: "The intention was always to have everything ready in time for a grand opening on 25 January. It's apparent that is not going to happen."
Funding for the new museum and related improvements to Burns heritage was formally announced a year ago.
The former Scottish Executive committed £5.5m and the Heritage Lottery Fund (HLF) another £5.8m.
The lottery distributor made an initial commitment but it is now up to the NTS to make a detailed bid for the cash. It will do so next month.
A spokeswoman for the trust said: "This has caused a delay of four months.
"As a charity, NTS has also had to ensure it fully satisfies the HLF and that its submission is of the highest quality, including the business plan."
The charity, which is trying to manage its way out of its own funding crisis, will also have to find other money to complete the project.
The cash from the Scottish Government and the HLF is not enough, even with a commitment in land from South Ayrshire Council.
The NTS spokeswoman said: "Both the trust and the Scottish Government are determined that the priority for the Burns Birthplace Museum is to offer a lasting legacy for Scotland, enhancing the timeless appeal of Burns and that this long-term perspective is what is important, not whether the museum is completed in November 2009 or into 2010."
The museum will be built in the car park of the current Tam O'Shanter Experience, a visitor centre owned by South Ayrshire Council close to the historic cottage.
It will hold 4,500 artefacts, including the original manuscript of Tam O'Shanter.
Meanwhile, the SNP MSP for Kilmarnock and Loudoun, Willie Coffey, is to ask the Scottish banks, the Royal Mail, the Royal Mint and the Bank of England to issue commemorative notes, stamps and coins in Burns' honour.
Mr Coffey said: "Robert Burns has made a huge contribution to literature and almost single-handedly saved the Scottish musical tradition in the 18th Century."