The work is being done by the Good Law Project and the Environmental Rights Centre for Scotland.
Charity and campaign groups have warned the Scottish Government that court proceedings could be on the cards if undisclosed climate figures are not revealed to the public.
Scottish Ministers are currently refusing to produce the full climate impact assessment of the carbon emissions expected to be generated by their £26bn Infrastructure Investment Plan – crucial to their pledge to reach net zero by 2045.
The Good Law Project and the Environmental Rights Centre for Scotland (ERCS) announced legal pressures on this last month. have now warned the Scottish Government that court proceedings could be on the cards if these figures are not revealed to the public.
The Scottish Government belatedly accepted that its failure to publish an assessment of the climate impact of its Infrastructure Investment Plan is in breach of the Climate Change (Scotland) Act 2009.
The Scottish Government has now pledged to undertake “urgent work” to remedy this.
It says it will publish its current emissions reduction targets and an assessment of whether the implementation of the Infrastructure Investment Plan will make it more or less likely these targets will be met.
But Scottish Ministers have so far not provided a transparent climate assessment to back up their claims.
Without quantifying emissions or showing their calculations, it is impossible to verify whether or not the Infrastructure Investment Plan is fully compatible with emissions reduction targets.
In their latest letter to the Government, Good Law Project and ERCS argue that Ministers must publish this information to comply with their legal duties.
Good Law Project Legal director, Emma Dearnaley, said: "Scottish Ministers need to show us how their flagship plan will meet vital climate targets. They’ve said they are committed to reducing emissions but words are not enough - we need to know that their plans will actually deliver so that crucial targets to reach net zero can be met.
“It is heartening that they’ve accepted they’re in breach of their legal duties and promised to remedy the situation. Now they must make good their shortfall - and we’ll be standing by and ready to take legal action if needed.”
The letter warns that without Ministers’ co-operation on this matter, the prospect of court proceedings could be on the table.
Dr Shivali Fifield, Chief Officer at ERCS, said: “Decisions made about infrastructure today will shape Scotland for decades to come, and it is in the national interest to ensure full transparency so that we can scrutinise the impacts. With £26bn of public funds at stake, it is essential that plans align with Net Zero commitments and meet the standards expected by the Scottish people.
“We are glad the Scottish Government has promised to fix the legal breach we have identified, but there is too much dithering and their actions still fall short of what is required. The government must clearly demonstrate their emissions calculations and how these will meet the targets set out in their Climate Change Plan.”