Barclays Bank is facing a formal complaint over its financial links to a coal-fired power station near the Sundarbans, the world's largest mangrove forest, which spans Bangladesh and India and is home to millions of people. Three complainants have submitted a case to the UK government's Office for Responsible Business Conduct, alleging the bank breached international guidelines by underwriting companies involved in the Rampal power plant, which campaigners say is polluting the Unesco world heritage site with heavy metals and contributing to climate risks that threaten the region's role as a natural storm barrier.

The complaint, supported by King's Legal Clinic, says Barclays underwrote debt for India's state-owned NTPC Ltd, a joint-venture partner in the plant, and bond issues for the Export-Import Bank of India between 2016 and 2019, which loaned funds to the project. A study last November found elevated mercury and arsenic levels in Sundarbans waterways, particularly the Pasur River beside the plant, while Unesco warned in 2016 that pollution could "irreversibly damage" the site. Campaigner Sharif Jamil argues Barclays failed to conduct adequate due diligence and should redirect financing towards renewable energy, noting other banks, including French institutions, declined to back the project.