I have one small question about this joyous new union: what point does it serve? - Euan McColm

Brace yourselves, for a new era dawns.

After years as the SNP’s most loyal poodles, the Scottish Greens stand on the brink of power. Loyalty really does have its rewards.

A cooperation agreement between the parties will see the Greens given two ministerial posts in return for their support in key budget votes.

It’s been hailed a historic development by both parties. For the Green Party, it will be a first time in power in any UK parliament. For the SNP, it will be a first formal agreement for government involving another party.

First Minister Nicola Sturgeon (centre) and Scottish Green Party co-leaders Patrick Harvie (left) and Lorna Slater (right) at Bute House, Edinburgh. Picture: PA

Far be it for me to put a dampener on nationalist celebrations of this unprecedented agreement between the SNP and the Scottish Greens, but I have one small question about this joyous new union: what point does it serve?

All smiles at a press conference on Friday, First Minister Nicola Sturgeon and Scottish Green co-leaders, Patrick Harvie and Lorna Slater, explained their shared rationale for this new arrangement.

This deal - the Bute House Agreement - said Sturgeon, was about "doing politics and governance better to find the solutions needed to solve the problems confronting the world today”.

"The spirit of co-operation and consensus-building is very much in keeping with the founding principles of our Scottish Parliament,” she added. While the parties might not agree on everything, they were coming out of their comfort zones to focus on what they do agree on.

Harvie said this “historic” agreement could not have come at a more important time.

He said: "We must build a fairer and compassionate country and we must do everything in our power to tackle the escalating climate and nature emergencies to deliver a just transition for all. That is what this deal will do”.

It was all terribly inspiring.

But examine the agreement and questions quickly emerge.

The deal between the SNP and the Scottish Greens in heavily caveated. In a number of areas, Green minister will be excused from ministerial responsibility. A footnote, headed “Excluded matters” reads: “While we share an ambition that Scotland should be a wellbeing economy that measures its success by reference to environmental and social objectives as well as economic objectives, the role of Gross Domestic Product measurements and economic principles related to concepts of sustainable growth and inclusive growth are excluded from this agreement.”

In their manifesto for this year’s Holyrood elections, the Scottish Greens warned against the pursuit of endless economic growth. It is perfectly clear that the SNP and its junior colleagues hold fundamentally different positions on the economy. The nationalists are in favour of economic growth and the Greens - like the cranks they are - are against it.

A significant weakness of Sturgeon’s is a failure to fully engage with the business community. It is hard to imagine the promotion of Green MSPs to the ministerial ranks will do much to convince wealth creators the Scottish Government has their best interests at heart.

One Sturgeon ally tells me the agreement is all about heading off any coincidence votes while another insists this is a case of refreshing the Scottish Government.

If the first is true, then the First Minister may have acted in haste. As the second largest nationalist party at Holyrood, the Scottish Greens depend on the votes of people see independence as a necessary step if Scotland is to do its politics differently. Under what circumstances, then, would the Scottish Greens side with the Tories in a confidence vote. That’s the sort of thing that would send support for the party plummeting.

On the question of confidence votes, Sturgeon could have taken the Greens for granted.

As for this being a matter of refreshing the government, well, if this is so, it’s a tacit concession that the Sturgeon machine was beginning to look a little worn out.

I’m sure Green negotiators who struck this deal think themselves terribly clever for including caveats which will free their ministers from responsibility for decisions with which they disagree.

Don’t we all recall how, after going into coalition with the Tories in 2010, the Liberal Democrats were sable to maintain their distinctive identity and win plaudits for achievements they made in government?

Of course, we don’t recall that because that’s not what happened. Rather, the Lib Dems lost their identity and were brutally damaged by association with policies their supporters deplored.

The Greens can withdraw support on any number of issues with they find difficult but they won’t be able to outrun the fact that their guarantee of budget support is enough to let the SNP do any number of distinctly ungreen things.

Central to the cooperation agreement is a commitment from both parties to hold an independence referendum during the current parliamentary term.

It has been abundantly clear for some time that there will be no referendum before the next election. Prime Minister Boris Johnson retains the power to stage a referendum and he has repeatedly ruled one out.

The decision of the SNP and the Scottish Greens to formalise their long-standing relationship does nothing to change that reality.

Opposition parties had great sport hurling rocks at the new political partnership on Friday. This was a “coalition of chaos” said the Tories.

SNP Health Secretary Humza Yousaf wasn’t having this. The “hysterics" from the opposition, he tweeted, betrayed how worried they were about the agreement. Oh, the whiff of pathos.

The SNP-Green deal is pointless and risky. Opposition parties should be delighted by it.