The UK advertising watchdog is preparing to warn HSBC about using adverts to greenwash its reputation and order it to be more transparent about its contribution to climate change, in a ruling that could have wide implications for financial sector marketing.

In a draft recommendation seen by the Financial Times, the Advertising Standards Authority deemed that HSBC misled customers in two adverts by selectively promoting its green initiatives, while omitting information about its continued financing of companies with substantial greenhouse gas emissions.

The adverts, which attracted 45 complaints, were published by HSBC at bus stops in Bristol and London in October last year. One said the bank would provide $1tn in financing for clients to transition to net zero, while the other pledged to plant 2mn trees to trap 1.25mn tonnes of carbon.