Fears are growing that the new Queensferry Crossing will not be ready by the revised completion date at the end of May.
The opening of the £1.35 billion bridge over the Forth has already been postponed once.
It had been due for completion at the end of last year, but the Scottish Government announced in June that it would not meet the timetable due to bad weather.
There are now less than ten weeks to go until the revised completion date at the end of May and 200 extra workers are understood to have been working on the bridge since the start of the year.
But much of the remaining work, including waterproofing the bridge’s deck and removing the cranes and other temporary structures, requires favourable weather conditions.
Scottish Conservative Transport spokesman Liam Kerr has tabled questions in the Scottish Parliament seeking assurances there will be no further delays.
He said: “The last time there was speculation of a delay, the Scottish Government was slow to respond but eventually set out a new timetable for delivery.
“We are now edging closer towards the expected date but again there seems to be some doubt as to whether the project will be finished within the timescale suggested.
“I think MSPs and the public have a right to know what is happening.”
A Transport Scotland spokesman said: “The contractor, is making every effort to open this iconic structure at the earliest opportunity.
“Extra resources have been brought in and an additional 200 people have been working on site since the turn of the year.
“Wind conditions over the past few weeks have been challenging for the contractor. During spells of difficult weather our contractor continues to focus on the areas of the project less affected by these conditions.
“We also understand that the forecast looks set to improve towards the end of this week. “As things stand the target date for opening to traffic remains the end of May.
“However, as has been said on many occasions, severe weather will always be a factor, and continues to have an impact on construction.
“Health and safety is the number one priority on the job and we remain fully focussed on completing the work safely. Our contractor is currently analysing its programme and we expect to be able to announce the date for opening to traffic soon.”