Embattled heritage charity the National Trust for Scotland last night faced mounting criticism over its response to a critical report, revealed in The Herald yesterday, which warned that its future is under threat over its commitment to build a new museum dedicated to Robert Burns.

Helen McArdle and Jennifer Cunningham

Embattled heritage charity the National Trust for Scotland last night faced mounting criticism over its response to a critical report, revealed in The Herald yesterday, which warned that its future is under threat over its commitment to build a new museum dedicated to Robert Burns.

Prospect union, which represents 90% of the charity's 450 staff, had lambasted the trust, which has nearly 300,000 members, in the document for moving to close 11 properties and cut around 90 jobs. It said the organisation was "on its knees" at the same time as it was planning to build the Robert Burns Birthplace Museum in Alloway, Ayrshire.

Kate Mavor, the chief executive, who during two months in the hottest seat in Scotland's heritage sector has been at the centre of a storm of unease over the management of the charity, has said that in future it must be the right size to carry out its core responsibilities.

The announcement of a programme of redundancies and the closure or part- closure of 11 of the trust's properties only days after she took up the post at the beginning of March has resulted in bitter criticism from many of the 300,000 members and a petition calling for an extraordinary general meeting.

Yesterday she refuted the allegations that taking on the running of the new museum with a commitment to raise £7m towards the £21m funding had diverted funds or staff energy away from their existing portfolio of properties. The trust has raised £3.2m for the Burns project - its biggest ever - and has to find another £3.8m.

Ms Mavor said: "What could be more important to Scottish heritage than Burns? The museum is one of our legacy projects and it is important that we get it right.

"The yardstick of success for me will be if it provides access for everyone and if every schoolchild in Scotland makes a pilgrimage to it at some point.

"We are in the business of myth-busting and there are many myths around Burns, but it is important to show that he had ideas before his time and influenced people across the world."

The museum is now delayed until 2010 and facing a £3.8m shortfall despite funds being "steered towards Burns" to the "detriment" of other assets, the report, which was compiled for the trust's board, added. It said that the trust was now mired in a financial crisis.

Alan Denny, Prospect's union representative for the NTS, yesterday met with the Culture Minister Michael Russell, who he said was "taken aback" by the allegations. He said: "They've basically said nothing and told us we don't know what we're talking about ... I think our members will be thoroughly disgusted."

Labour's culture spokeswoman, Pauline McNeill, said the debacle over the Burns museum "reflects badly" on the Scottish Government's Homecoming celebrations this year, but she said state intervention should be a "last resort".

Ms McNeill said: "I would certainly call on the National Trust to get its house in order."

Peter Drummond, national director of Architectural Heritage Society of Scotland, said: "The reasons behind the current problems are many, however stakeholders all standing in a circle and pointing at each other is unlikely to be of benefit."

The Scottish Government said: "We share the general worry about the future of the NTS and are seeking further meetings in light of this report."