The cost of a Cliffs of Moher interpretative centre has now climbed to €31.45 million, with Clare County Council facing an estimated €4.45 million shortfall in funding for the scheme.
The revised cost of the centre, confirmed by project leader Ger Dollard, is more than eight times the original estimate of €3.8 million put on the scheme in 1990 when plans were first mooted.
The council only lodged plans for the scheme in 2001 after securing the necessary land from the local Considine family. In part-return the Considines will operate a shop in the centre.
In the 1960s the Considines rejected a bid from a German company to buy 60 acres that would have given it ownership of land over the cliffs.
Work started on the council's two-storey centre last April, and the facility is expected to open in the first quarter of 2007.
The council has secured €10 million in grant aid from Fáilte Ireland for the scheme.
It also has approval from Government to secure a loan of €15 million and has a historic investment of €2 million, leaving a shortfall of €4.45 million.
To date, consultants have been paid €1.7 million for their work.
Cork firm Rohcon is being paid €21.7 million to construct the centre and put in place ancillary facilities.
In a bid to bridge the funding shortfall, Mr Dollard said the council had an application for additional grant aid with Fáilte Ireland based on the actual tender received as opposed to the estimates originally submitted.
He also confirmed that the council was seeking a corporate sponsor for the project, either in Ireland or elsewhere.
"We are putting in place a separate company structure to manage the commercial aspects of the operation and allow VAT reclaim."
Newly-appointed manager of the visitor centre Katherine Webster said she expected visitor numbers to the centre to top 800,000 in its first full year of operation.
As part of the project, the council is to also seek World Heritage Site designation for the cliffs.
Meanwhile, the council is taking legal moves to ensure that music is a thing of the past at the cliffs.
The local authority is serving solicitor letters on buskers who play at the cliffs, demanding that they no longer play.
According to the council, the musicians are operating without permission on council property and are, therefore, trading illegally.