Two influential China hawks in the US Congress and UK parliament have accused HSBC of oppressing Hongkongers over pension rights if they want to emigrate, in a sign of the pressure on the bank as it straddles western and Asian markets.Mike Gallagher, the US Republican representative and chair of the House China committee, and Alicia Kearns, the Conservative MP who heads the UK foreign affairs select committee, wrote to HSBC on Friday to express “deep concern” that the bank was barring some Hong Kong residents from making early pension withdrawals if they want to move abroad.

“We are concerned that HSBC — in support of the Hong Kong National Security Law — is withholding pension funds from BNO [British National Overseas] passport holders and thus contributing to the oppression of people in Hong Kong,” they wrote to HSBC chief executive Noel Quinn, in a letter obtained by the Financial Times.

The pressure from the lawmakers highlights how difficult it is becoming for HSBC to operate from twin bases in Hong Kong and the west as geopolitical tensions rise. The bank pulled out of US retail banking two years ago but depends on the US for its dollar-clearing licence, which is essential to its huge global trade financing business.