The Queensferry Crossing has been hit by further delays meaning it is likely to be August before its completed.
The opening of the bridge has been delayed again because of “adverse weather conditions”.
Economy Secretary Keith Brown told MSPs on Wednesday the expected opening date would now fall between mid-July and the end of August which he admitted was “disappointing”.
Mr Brown was updating the Scottish Parliament’s rural economy and connectivity (REC) committee.
The £1.35bn megastructure was originally due to open in December last year but that date was postponed because of “strong winds”.
The minister said the latest problems were due to strong winds hampering the dismantling of the tower cranes and other ongoing activities. The cranes can only be removed in wind speeds of less than 25mph. Mr Brown said the first of the three cranes had taken 65 days to take down rather than an expected 15 days.
He said: “Today there are only nine weeks remaining to the end of May and the review has concluded that even with the best weather this date is not now safely achievable.
“There is no additional cost to the public purse and the Forth Road Bridge continues to carry traffic over the Forth during these final weeks of construction.
“While its clearly very disappointing the new bridge won’t be ready ahead of the contractual completion date, I believe it is important to take the time to make sure the bridge is built in the safest possible circumstances to the highest possible standards.”
Sally Cox, chairperson of the Board for the Forth Road Crossing Bridge Constructors (FCBC) said: “FCBC acknowledge that the uniqueness of this project and the onerous weather conditions it has experienced, particularly working at height crossing the Forth have created more challenges than we anticipated.
“FCBC have always been and remain ambitious about completing this challenging project at the earliest possible date and share Transport Scotland and the public’s frustration over this delay.
“We have assured Transport Scotland that every endeavour is and will continue to be made, to safely complete the project at the earliest opportunity.”