The firms say they are behind numerous 600 jobs the wind farm will create. It was originally consented by Scottish ministers in 2014.
The conservation charity said on Tuesday it has approached the highest court in the United Kingdom for permission to appeal against the recent decision of the Inner House of the Court of Session to approve the four projects in the firths of Forth and Tay.
Mainstream Renewable Power, the developer of the 450-MW Neart na Gaoithe, said that work on the wind farm is expected to begin in 2018 after RSPB last month failed to succeed in its latest attempt to attack consent for scheme. Highly-skilled jobs, vital apprenticeships and the socio-economic benefits of this project are all at risk for the hard-pressed communities within the region.
Companies involved in the coalition include 8.2 Aarufield, Atkins, BiFab, Butler Land Management, COWI, CG Global, CS Wind UK, Energy and Water Associates, Eyemouth Harbour Trust, Facilitating Change, Found Ocean, Global Energy Group, GeoSea, GD Geo, Houlder, James Fisher, Mainstream Renewable Power, Montrose Marine, Obelisk, Oceaneering, Partrac, Scotia Supply Chain, Searoc, Seaway Heavy Lifting, ST3 Offshore, Taylor Hopkinson Associates, Tymor Marine, Xero Energy and Young Planning and Energy Consenting.
He added: "This is about real people, real jobs and real environmental benefit. Scotland can not afford to put nationally significant infrastructure projects at risk". That is why RSPB Scotland has worked with the Firth of Forth offshore wind developers and Scottish ministers for nearly 10 years to try and help offshore wind progress in a manner that minimises impacts on seabird colonies.
"We have not taken this decision lightly, however our concerns with the manner in which Scottish ministers' took their decisions in 2014 remain undiminished", she said.
"We are hopeful that our application is successful and that we are granted leave to appeal so these important issues of public interest can be considered in detail by the Supreme Court".