The Scottish Greens are to actively oppose the introduction of two green freeports North of the border.
This is the party's first major split from the SNP since a co-operation agreement was announced last summer.
It was announced yesterday that a partnership agreement to establish two green freeports in Scotland had been reached between Scottish and UK Ministers.
Green freeports are expected to help inject billions into local economies.
However, the Scottish Greens have criticised the plans as "greenwashing".
Finance spokesman Ross Greer told the BBC that his party wanted nothing to do with "these so-called green freeports".
He said: "There is nothing genuinely green about them. Freeports are a really effective way to give tax relief and throw public money at multinational companies who are already doing their best to avoid tax.
"The SNP used to oppose freeports for exactly the same reason the Scottish Greens still do.
"Internationally, freeports are associated with crime, money laundering, smuggling, low wages."
Mr Greer said that there was "no actual solid requirements" to meet climate targets or stick to fair work practices, and that it was "naive" to expect large corporations to adhere to these rules.
He claimed that freeports were not good for the environment, and added: "So not only will we not help introduce them. We will actively oppose their introduction.
"The Greens will have nothing to do with this corporate giveaway. Instead of working with the Tories, we would urge SNP colleagues to collaborate with those of us who want to build an economy which serves, rather than exploits, people and the planet."
Locations which have expressed an interest in bidding for the green freeports include Aberdeen, Peterhead and Cromarty Firth.
Winners will be announced over the summer.
UK Ministers are expected to provide up to £52m in seed funding to help establish the facilities, which is in line with funding offered to freeports across England.
The Scottish Government will support the significant tax reliefs that will be made available to green freeports through devolved tax levers, including rates relief.
Meanwhile, HMRC will provide support which includes enhanced tax allowances, Employer National Insurance relief and customs duty reliefs.
Scotland's Economy Secretary Kate Forbes said yesterday: "I am pleased we have been able to reach an agreement on a joint approach that recognises the distinct needs of Scotland's economy and enshrines the Scottish Government's commitment to achieving net zero and embedding fair work practices through public investment.
"The Scottish Government will have an equal say on all bids, and will expect bidders to adhere to fair work practices, including payment of the real living wage."