The group said that BP frequently presents itself as “part of the climate solution” in its ads, which typically show wind turbines and other forms of renewable energy. But ClientEarth said that 96 per cent of the company’s annual spend is on oil and gas projects and it is one of the world’s biggest polluters.

They advocate a “tobacco-style warning” which lets consumers know that claims the company is rapidly transitioning to clean energy are largely misleading.

The environmental legal charity has triggered an official complaint under the guidelines of the Organisation for Economic Co-operation and Development (OECD), an international set of rules governing corporate conduct.

The complaint is being submitted to the Government’s UK National Contact Point, which is responsible for implementing the complaints mechanism relating to the guidelines.

ClientEarth climate lawyer Sophie Marjanac said: “BP is spending millions on an advertising campaign to give...