Seven million pound increase since April
Tynwald members will be briefed on why there has been a £7 million increase in the capital cost of the proposed Liverpool landing stage.
In April the cost of the new facility - half a mile from the historic Pier Head site - was given as £31.3 million.
However, Tynwald will be told next week that the capital cost is now just over £38 million.
No explanation has been given as yet as to the reason for the rise.