The global practice is involved in the revamp of Scotland's Supreme Court, situated on Edinburgh's Royal Mile, but has been repeatedly snubbed by builders due to the complex and risky nature of the project.
Mackie said: 'It is an A-listed building and the project will have to take place over five years while the building stays operational. It means it will be particularly difficult work with all these added restrictions.'
The Scottish Courts Service (SCS), which owns the building, has had to re-advertise the tender due to the lack of interest, and there are concerns that the longer the project drags on, the less likely it is that builders will want to get involved.
Already worried by the delays and cost, the SCS froze the scheme in 2004 for a re-evaluation. However, despite the re-evaluation and the £35 million fee, contractors are still unforthcoming.
The Supreme Court has been the hub of the Scottish justice system since 1632. It is thought that the scheme's tight site may be another reason that contractors have been unforthcoming.