He added: “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.”

The dispute will not sink the SNP/Green government as freeports were specifically excluded from a deal they signed last year, meaning the parties can still disagree.

The SNP had initially said they would not agree to freeports being set up in Scotland unless they were rebranded ‘Greenports’ and businesses were mandated to pay the real living wage.

However, after a dispute that lasted more than a year, the two governments settled on the name ‘Green Freeports’. The UK Government will pay £52 million in seed capital for both ports and the Scottish Government will offer incentives to businesses through devolved taxes.

Ivan McKee, an SNP junior minister initially in charge of negotiations, had publicly expressed many of the same concerns as the Scottish Greens. However, Ms Forbes took control of the talks and struck a deal which it is hoped will see the two freeports up and running by next year.

Disappointed

On his visit to Scotland on Monday, the Prime Minister praised the SNP government for striking a deal, saying its attitude had been “fantastic” and that Nicola Sturgeon’s administration now could “see the advantages” of freeports.

A bidding process will begin soon, with the UK and Scottish governments having an equal say over which will succeed.

Liam Kerr, the net zero spokesman for the Scottish Tories, said the row was “all too typical of the student level politics the Scottish Greens enjoy reveling in.”

He added: “It was welcome the SNP Government put aside their longstanding opposition to freeports and worked with the UK Government to ensure two ports will now get the go-ahead in Scotland.

“What a pity the Greens couldn’t join their coalition partners and welcome this change in policy. Freeports can help to kickstart our recovery and deliver a significant boost to economic growth.

“Scotland’s economy works best when both of our Governments work together rather than resorting to grievance, which this time came from the Greens.”

Rigorous process

Speaking to the BBC, Ms Forbes said any bidder that did not promise to pay the real living wage “would not win”, even though there is no specific obligation for them to do so. Businesses would also have to display a commitment to reaching net zero emissions, she said.

Ms Forbes said: “Green freeports are excluded from the cooperation agreement with the Greens. When it comes to the approach we have taken, it is very distinctive to the approach that is being taken elsewhere.”