BRITAIN should sign a formal agreement to co-operate with China on fighting climate change, a think tank has recommended.

Researchers at international affairs think tank Chatham House urged ministers to deepen climate co-operation with Beijing, saying the “with us or against us” approach “belongs in the cold war.”

In a paper due to be published next week, Chatham House said a formal deal would enable “bolder and more confident engagement,” allowing Britain and China to better share expertise.

Jiangwen Guo, one of the paper’s co-authors, said: “The UK and China have a long history of successful collaboration on climate change.

“With rising geopolitical instability, and a retrenchment of climate leadership in some quarters, they have an opportunity to demonstrate the benefits of bilateral co-operation, and in so doing shore up multilateralism and accelerate practical climate action, which is in all our interests.”

The call comes as Chancellor Rachel Reeves holds a series of meetings in Beijing and Shanghai aimed at improving economic relations with China.

Her visit is the latest example of Labour’s softer approach to Beijing after a freezing of relations under former prime minister Rishi Sunak.

The Chatham House paper suggested greater co-operation on areas such as emissions trading and carbon budgeting, deploying low-carbon technologies and adapting to the risks posed by climate change.

But the authors also acknowledged the challenges posed by the incoming Donald Trump administration in the US, saying the new president’s harder line on China could pressure Britain into abandoning co-operation in all areas.

They said: “To be successful, any new phase of UK-China climate co-operation must therefore account for these challenges and be designed in such a way that it is resilient to the inevitable political turbulence it will encounter.”