One of the largest labour unions in the US is trying to oust Bank of America chief Ken Lewis as part of a campaign to organise tens of thousands of employees across the financial services industry.

The Service Employees International Union, which has 2m members, released a four-minute video on Thursday urging BofA shareholders to “fire Ken Lewis”. The video coincides with a proxy campaign waged by Change To Win, which represents the pension investments of seven unions, including the SEIU, which has called for the removal of Mr Lewis and Temple Sloan, BofA’s lead director, at the bank’s shareholder meeting on April 29.