The gallery and museum revamp, which McLaughlin and Harvey began back in 2015, was initially scheduled to be completed in late 2017 at a cost of £30m. Completion was then put back by at least a year.

Funding was to be raised evenly from the Heritage Lottery Fund, Aberdeen City Council and through a public donations drive.

However, according to The Press & Journal, a report set to go before the council’s capital committee next week reveals that the drive has netted just under £4m while the gross budget has been increased to £34.6m.

The council may be called on to pick up the bill if a financial settlement cannot be agreed with main works contractor McLaughlin and Harvey.

The report reads: “Informal meetings are being held with the contractor to agree a final figure which will incorporate a review of their supporting information.

“Officers from legal services are monitoring matters in order to protect (the council’s) position. Officers have access to expert legal advice from construction law specialist lawyers should that be required.

“The overall philanthropic fundraising target is £20m of which £13,814,329.37 has been raised to date. This comprises £10m from the Heritage Lottery Fund and £3,814,329.37 from other trusts and grant-awarding organisations and public donations.

“The final expenditure can only be confirmed once all the project works are complete. A key element in achieving this will be reaching an agreed financial settlement with the main works contractor.”