Construction of the £1.3bn Queensferry Crossing has been hit by a five-month delay due to bad weather conditions.
The project was scheduled to finish in December this year but Scottish economy secretary Keith Brown said the deadline will not be met.
He said the delay was down adverse weather conditions and work would not be finished until at least mid-May 2017.
Strong winds are understood to have affected the bridge deck and cable installation.
A consortium of Dragados, Hochtief, American Bridge International and Morrison Construction was awarded the £790m contract in 2011.
Known as the Forth Crossing Bridge Constructors, the group was tasked with building the bridge linking Lothian to Fife.
The team has lost 25 working days in the last two months alone due to the poor weather conditions.
Work was also suspended on the project’s north tower after one man died and another was injured while working on the bridge in April 2016.
The consortium brought in more than 100 extra workers, increased working hours and altered construction methodologies in an effort to hit the December delivery target.
Mr Brown said FCBC was still confident it could achieve completion by May and that a plan was now in place to ensure this was achieved.
This will include fortnightly updates from the consortium to Transport for Scotland on the project’s progress.
Mr Brown said: “We will continue to work closely with the contractors and I will personally ensure that every pressure and every resource is brought to bear to deliver or even better the revised target date of May 2017.
“We have always been ambitious about this project and have always worked towards a deliberately ambitious target. However, it is important to recognise that FCBC still fully expects the project to complete within the timeframe of their contract.
“This project is not late and there will be no impact on the public purse.
“The December 2016 target date was set to address concerns about the long-term condition of the Forth Road bridge where it was originally believed that it would be restricted as early as 2017.
“These concerns have proven to be less immediate and the recently installed structural health monitoring system is providing assurance on the ability of the FRB to sustain traffic.”