Advisers at No.10 and the Cabinet Office have been seeking to sideline the role of Scotland’s First Minster in the global gathering, The Independent reported.
According to meeting notes and WhatsApp messages seen by the newspaper, strategists have been trying to work out how to prevent the summit from becoming an “advert” for Scottish independence.
Responding to the reports, Ms Sturgeon said anyone who allows politics to get in the way of tackling climate change would be abdicating responsibility.
She wrote on Twitter: “All that matters is that COP26 delivers an outcome to meet the Paris Agreement of limiting global warming to 1.5 degrees.
“We must work together and maximise contributions towards that.
“Anyone – me or PM – who allowed politics to get in way would be abdicating that responsibility.”
COP26 is due to take place in Glasgow for two weeks from October 31, and will see global leaders descend on the city.
But the leaked messages suggest advisers are planning to keep Prime Minister Boris Johnson from sharing a platform with Ms Sturgeon in the run-up to and during the event.
Mr Johnson should “neutralise” the First Minster by including other devolved leaders where possible, they said.
One adviser’s message referring to Ms Sturgeon read: “This can be labelled as a role for her [as one of the UK’s leaders], but avoids her taking centre stage.”
Another said: “We can’t let this be used as an advert for an independence campaign.”
The notes also document efforts to ensure that the union flag is displayed as much as possible at the summit.
A Scottish government source had told The Independent the plan said “far more about the prime minister and those around him than it does about the first minister”.
“COP26 in Glasgow is a vital occasion in the global fight against climate change – the world is at ‘code red’,” the source said.
"That is what we should all be focusing on, instead of pathetic and puerile attempts at point-scoring, which simply demonstrate the depth of Downing Street’s paranoia.”
A UK Government spokesman said: “The Prime Minister has been clear that there is a role for all the First Ministers from across the UK at COP26 and we are working together with the Scottish Government to ensure this crucial summit is a success.”
The advice was reported after climate activist Greta Thunberg has said she did not believe Scotland was a world leader on climate change, as the Scottish Government claims.
The Swedish teenager said she had not yet decided whether she would travel to the global UN climate conference in Glasgow, but would do if it is “considered safe and democratic”.
Scottish Greens co-leader Lorna Slater has separately expressed concerns the COP26 summit will be an “exercise in backslapping and greenwashing”, adding: “I think that Boris Johnson has invited the world’s worst polluters, the big corporations, and he’s abdicating responsibility and handing it to these big corporations to solve the problem.”