Scottish Greens will be weighing any potential damage to their party's brand and electoral fortunes - and the chances of Humza Yousaf remaining as SNP leader and First Minister - when they decide whether to stick with the Bute House Agreement next month, The Herald has been told.

The member said a future vote in Holyrood on legislation to drop the 2030 target would be "very much on members' minds" as both Patrick Harvie and Lorna Slater as government ministers would be required to support the move.

The consideration is being given as the party prepares for a vote on the BHA at an extraordinary general meeting of the party called after demands by members following the scrapping of a key pledge to reduce carbon emissions by 75% by 2030 from their 1990 level.

Speaking to The Herald one member said among the issues activists will be looking before making their decisions will be any implications for their party if Mr Yousaf has to step down as SNP leader and First Minister faced with own internal difficulties in his party.  Kate Forbes, seen as a possible successor to Mr Yousaf, said last year the BHA “should be repealed and the SNP should operate again as a one-party minority government”.

The Green activist spoke out after the Herald on Sunday revealed that the SNP is looking to a future leadership contest amid fears over how the party will do at the general election expected later this year.

"There is the possibility that Humza Yousaf will go after the UK general election. So would it make more sense for us to leave now and repair any reputational damage that we've had within the next two years, or wait and be potentially kicked out of government by whoever becomes First Minister?" they said.

Other factors shaping members thinking ahead of the EGM vote included what measures were being proposed to get the climate action they want; what the government was doing to support trans health issues, and the NHS more widely, as well as tackling the cost of living and supporting the economy.

The member also told The Herald that there was concern in the party that a vote in favour of abandoning the 2030 target by Mr Harvie and Ms Slater could damage the Scottish Greens brand and electoral fortunes. Environmental campaigners have been highly critical of the scrapping of the pledge/

Under the co-operation agreement Mr Harvie and Ms Slater are required as junior ministers to support government legislation and would be expected to resign their roles if they cannot do so.

As the target to cut carbon emissions by 75% is enshrined in law, ministers will need to bring in new legislation to overturn an existing law.

It is understood the government plans to bring forward legislation to drop the 2030 target before the summer recess begins in June.

Amid angry from Greens activists the member told The Herald that voting for the legislation could damage the party's brand and cause it to lose support.

"It could have a really damaging electoral impact," they said.

"We are the Scottish Green party, if we are not going to be seen to be standing up for the environment, who will?"

They added: "Voters look to us to stand up for the environment. This potentially has really damaging consequences for not only our brand but also for their faith in our political system."

Asked what would happen if Mr Harvie and Ms Slater vote to drop the 2030 target, another member said the move would provoke '" lot of anger".

They said: "I think there would be a lot of anger and I think that anger would perhaps be directly perhaps less at the Bute House Agreement and perhaps more at the leaders themselves.

"I think that would not be in a position that they would want to find themselves in."

Cabinet secretary for net zero Mairi McAllan said the 2045 target remained for Scotland to be carbon neutral as she set out a package of measures aimed at delivering that ambition.

They included plans to deliver a new national integrated ticketing system for public transport, as well as he setting up of a climate assembly, a trebling the number of charging points available for electric vehicles, in a bid to encourage more people to switch away from petrol and diesel cars.

Edinburgh city councillor Chas Booth said last night he would be looking closely at the details of the Scottish Government's new proposals.

He said the dropping of the 2030 target was not unexpected following the report last month by the Climate Change Committee. However, he wanted to know what would be replacing the 2030 target.

"Anyone who has read last month Climate Change Committee report will recognise that it is no longer feasible to meet the 75% target by 2030. I think everybody accepts that.

"What I would find difficult to accept is if the Scottish Government were to remove that and not replace it with anything else.

"There was talk in the ministerial statement of five year carbon budgets. It's not clear to me that these would be legally binding or how ambitions it would be.

"What I will be doing as a member going into the EGM, I will be looking for more information about what will replace the 2030 target."

Appearing on BBC Scotland yesterday Mr Harvie admitted he did not know if the pact with the SNP will continue.

"This is a moment that is critical for the future of climate policy in Scotland, which is, you know, the reason Greens are in politics in the first place," he said.

"It's critical to the future of our party as well, and over the next few weeks we have probably the most important decision to make that we've ever had to make about the future of our party.

"And I want to make sure that we're all listening to each other and making sure that we genuinely understand and share, not just the sense of urgency and the deep disappointment and anger about the fact that Scotland is not on track at the moment, but a focus and determination on action."

He said he feared if his party voted to pull out of the agreement it would "strengthen" the position of SNP critics of the BHA such as Fergus Ewing, who has opposed several policies championed by the Greens.

"My worry is that, if we if we walked away at this point, we would decelerate the climate action, we would see the hand strengthened of the likes of Fergus Ewing, backbencher in the SNP now, who's constantly popping up and having a go at environmental policy and urging the Government to slow down," he said.

He cited achievements including rent controls, scrapping peak-time rail fares, and free bus travel for young people,

Scottish Conservatives chairman Craig Hoy said: "Patrick Harvie takes no accountability for his party's shameful record in Government.

"Both he and Lorna Slater (minister for green skills, circular economy and biodiversity) have spent the last three years pitifully trading environmentalism for nationalism to the fury of their members who now want out of this toxically incompetent coalition.

"(First Minister) Humza Yousaf is so weak that he has lost any authority he had, and even after the disaster they've been in Government, it's still the Greens calling the shots.

"If Humza Yousaf had any backbone, he would be pulling the plug himself on this shambolic deal which is harming Scotland's economy and jeopardising our oil and gas industry.

"Instead, he is at the mercy of the Green vote, and the coalition of chaos he inherited from Nicola Sturgeon is now hanging by a thread."