COP28 is officially the largest ever UN climate summit, with 80,000 participants registered on a list that -- for the first time -- shows who they work for.

Until this year, those taking part were not obliged to say who they worked for, making it tricky to detect lobbyists and identify negotiators' potential conflicts of interest.

Some 104,000 people, including technical and security staff, have access this year to the "blue zone" dedicated to the actual climate negotiations and the pavilions of the states and organisations present.

That largely exceeds the previous record at last year's UN climate summit in Egypt, COP27, which had 49,000 accredited attendees, and where oil and gas lobbyists outnumbered most national delegations, according to NGOs.

This year, there are nearly 23,500 people from official government teams.

Travelling with them are 27,208 policy experts, academics, representatives of professional organisations and senior company executives from oil giants.

These guests do not have the same degree of access to the negotiations as the official delegates, but their presence has raised concerns about the ability of big business to influence the talks.

Among the host country's guests are Bill Gates and Antoine Arnault, the son of LVMH boss Bernard Arnault, the second richest man in the world after Elon Musk, according to Forbes magazine.

The accreditations list also includes more than 14,000 non-governmental organisations, ranging from environmental groups to industry lobbyists.

In June, UN secretary-general Antonio Guterres said fossil fuel companies must "cease and desist influence peddling and legal threats designed to kneecap progress" towards preventing the planet's climate spinning out of control.

And organisers say some 400,000 people have registered to get a day pass to the vast "green zone" around the talks on the site of the Dubai Expo 2020, which has been turned into a huge fair showcasing businesses and environmental innovation.