THE opening of the Queensferry Crossing has been blown off course until between mid July and the end of August.

It's the second delay to hit the £1.35 billion project and there are no guarantees about those dates with completion dependent on the weather.

Economy secretary Keith Brown said strong winds had disrupted work and any extra costs would be borne by the contractors and not the taxpayer.

Addressing the Rural Environment Connectivity Committee in the Scottish Parliament, he said: "When I was here before I was asked to guarantee the May date and I could not do that.

"The weather is the master. We have a high degree of certainty in these dates but it's not an absolute certainty."

He added: "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.”

The bridge was to open in December last year but "adverse weather" pushed this back to May, although an unnamed worker told the Press less than three weeks ago that there was no chance of it being open by then.

Confirmation came after Forth Crossing Bridge Constructors (FCBC), who were asked to carry out a programme review, reported back on Monday.

Mr Brown said FCBC were then "interrogated" by Transport Scotland about the open to traffic date, now between mid July and the end of August.

The conclusion was that with only nine weeks until the end of May, and even with the best of weather, that date was "not safely achievable".

Mr Brown said it was a "huge disappointment" but added it was a "four to 10 week overrun on a six year project" on a bridge that was £250m cheaper than the original estimates and "already a world record breaker".

He also said: “I fully recognise the effort of the workforce in building this amazing new bridge. Over 13 million hours have gone into building the Queensferry Crossing over the past six years.

“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."

The 1.7 mile long structure, which will replace the Forth Road Bridge as the main road route between Fife and Edinburgh, is substantially complete and the last section of the deck was lifted into place in February.

The committee was told that the removal of the tower cranes could only be done at wind speeds of less than 25mph and should take 15 days.

When this is happening, it also means it is not possible to safely work within a 50 metre radius of the crane.

The removal of the north tower crane took 65 days as there were "fewer clear weather windows than expected".

Mr Brown said all remaining activities, including work on the cables, deck and road surface, were vulnerable to wind, low temperatures and rain.

He said FCBC have taken on an additional 200 workers, taking the workforce to 1,500 people, and are working 24/7 to get the job done.

Asked why, after what seemed like a mild winter, the project was delayed again, FCBC project director David Climie said: "We have to plan the work very carefully and rely on the weather forecast.

"It's not been a particularly bad winter for snow or rain, that's helped with the roadworks, and we haven't had a large number of storms, but the milder weather has meant we've had steady wind over a long period of time which has been a problem for a number of activities."

Sally Cox, chair of the board for 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.”

The government was commended for insisting on a fixed price contract, it runs out at the end of June, which means any additional costs will be met by FCBC.