A climate summit featuring devolved nations and regional mayors should be organised by the UK Government, according to a think tank set up by Gordon Brown.
Our Scottish Future is calling for a "CopUK" conference to set targets across Britain to cut carbon emissions.
Mayor of the Liverpool City Region Steve Rotheram and Mayor of South Yorkshire Dan Jarvis both back the idea, which seeks to agree a regulatory framework for a green transition and try to ensure UK spending is distributed fairly across the UK.
The proposal, put forward by former Scottish Green leader Robin Harper, wants the cross-party conference to set emission-cutting plans which should take place within 12 months.
Mr Harper warned that none of the UK nations "are currently doing enough to meet exacting targets to reduce carbon emissions", and he called for a more co-ordinated approach.
He added:: "The Cop26 conference in Glasgow demonstrated once again that we cannot make change happen in the world without making it together. New global commitments on coal, on deforestation, and on support for developing nations have emerged in the last two weeks.
"They are all examples of nations laying aside their narrow self-interest to work for the common good.
"We must ensure that this legacy is kept alive on our own shores over the coming months."
Mr Rotheram said: "Earlier this month, leaders from around the world came together at Cop26 to try and chart our planet's course toward net-zero.
"Throughout those two weeks, the Prime Minister and Government spoke a lot about co-operation and uniting in the face of the biggest threat any of us will ever face.
"Today, we're calling on the Government to show that same spirit of common purpose by bringing together leaders from within the UK to help supercharge our own march to net-zero.
"We should be setting an example for the rest of the world to follow.
"Mayors, councils and local leaders are at the forefront of the green industrial revolution. CopUK would allow us all to put party politics aside and work together for the good of our planet."
Mr Jarvis added: "To reach net-zero we desperately need local decision-making backed up by a nationwide strategy.
"Just as world leaders came together in Glasgow to set out plans for the world, we now need leaders across the UK to come together to map out a road to net-zero for Britain."