The number of delegates at this year's UN climate talks who are also linked to fossil fuel producers has quadrupled since last year, campaigners say.
Around 2,400 people connected to the coal, oil and gas industries have been registered for the COP28 climate talks.
This record number is more than the total attendees from the 10 countries most vulnerable to climate change.
The jump is partly due to registration changes with attendees now required to be open about their employment.
The analysis was carried out by a coalition of green groups opposed to the presence of delegates linked to coal, oil and gas at the talks.
COP28 is the biggest climate conference ever held with some 97,000 politicians, diplomats, journalists and campaigners registered for the meeting,
But this new analysis suggests that 2,456 representatives of the coal, oil and gas industries and related organisations are also at the gathering in Dubai, in the United Arab Emirates.
At COP26, in Glasgow, there were some 500 delegates with fossil fuel backgrounds.
Last year at COP27 in Egypt, the numbers had swollen by a quarter, with more than 600 representatives there.
But this year more than four times that number have registered for COP28.
Ahead of this year's talks, the UN introduced tougher registration procedures, meaning that more people had to state clearly who they worked for.
As a result of this greater transparency the numbers have shot up significantly. But campaigners say it is not the only reason for the rise.
"This does not account for the entire, significant uptick in lobbyist presence," said George Carew-Jones, from the Kick Big Polluters Out coalition.
"These talks are rumoured to deliver progress on a phase out of fossil fuels, and the fossil fuel industry is here to influence that outcome as much as possible," he said.
Campaigners go through the list of registered attendees at each COP and analyse the affiliations that participants self-disclose.
They then verify that each link has been sponsored or paid for by a fossil fuel linked entity, such as a company or national oil producer. They say they take a conservative approach and apply a "rigorous methodology".
The future of fossil fuels is very much on the agenda at this meeting, with COP president Sultan al-Jaber seeking to land a deal that might refer to the phasing out or phasing down of these energy sources.
His appointment has been controversial as he is also the CEO of Adnoc, the UAE's state oil company.
Mr Jaber has had to defend himself after making statements that appeared to cast doubt on the science behind the idea of ending fossil fuels.
Campaigners who compiled these new figures say that links to the oil, coal and gas industries at COP28 go far beyond the presidency.
"The sheer number of fossil fuel lobbyists at climate talks that could determine our future is beyond justification," said Joseph Sikulu, Pacific Managing Director, 350.org.
"Their increasing presence at COP undermines the integrity of the process as a whole. We come here to fight for our survival and what chance do we have if our voices are suffocated by the influence of big polluters? This poisoning of the process needs to end, we will not let oil and gas influence the future of the Pacific this heavily."
BBC