Hundreds of skilled jobs are at risk at the Fife and Western Isles-based engineering company, which has said it will shut down unless new contracts can be secured.
The 19 MSPs representing all five parties at Holyrood have signed a letter to Business Secretary Greg Clark, calling on him to do all he can to encourage the developers of the Kincardine Offshore Windfarm to award work to BiFab.
"During the recent threat of administration, we saw the dedication and value of BiFab’s workforce. Whilst the challenges at BiFab have been well documented in recent months, at no point have the skills, experience, commitment and determination of the workforce been in doubt.
"This highly skilled group of workers deserve our support and there are concerns that if no statement of intent regarding the awarding of a new contract is given, that these jobs will be lost to other areas or lost from the economy completely. This would be a tragedy for local communities and devastating for the local economies of the areas in question."
The letter goes on to say renewable energy "could provide a lifeline to revitalise our indigenous fabrication, engineering and steel industry base", but too much work in the sector leaves the UK.
"We are aware that there are a number of contracts coming up in the near future for fabrication work with the first expected to be the awarding of the Kincardine Offshore Windfarm Project.
"We would urge in the strongest terms that this contract take into account its wider responsibility to the Scottish economy and believe that BiFab would be best placed to receive the contract.
"We recognise that the decision on which companies will be awarded roles in these projects is not within the discretion of the UK Government and that it is a commercial decision... We are asking you and the UK Government to do all that you can to encourage contracts to come to BiFab."