The Methodist Church of Great Britain has written to HSBC calling for a re-think of its support for new security laws in Hong Kong.
It said the national security law, which came into effect in July despite widespread consternation, was a threat to democracy and human rights in Hong Kong.
HSBC's Asia-Pacific chief executive Peter Wong drew criticism in the West after signing a petition backing the law. In a social media post in China, the bank said that it "respects and supports all laws that stabilise Hong Kong's social order".
The Methodist Church said it had been a "long-standing client" of HSBC, with its Central Finance Board being a customer and shareholder.
In a letter, Matt Tattersall, the Methodist Church's Director of Finance and Resources, and David Palmer, the CEO of its Central Finance Board, expressed their "grave disappointment" at the bank's "continued support for the new security laws".
"These laws are contrary to the 1997 handover agreement with the United Kingdom, a threat to democracy, and interfere with human rights of Hong Kong citizens," they said.
"Your support of them is of deep concern to the Methodist Church and we urge you to reconsider your support of them as a matter of urgency."
The imposition of the national security law followed yearlong protests against China's increasing interference in the territory.
Christians have been among those voicing concern about the law's implications, with Hong Kong Cardinal Joseph Zen saying he was prepared to be arrested.
The 88-year-old, a vocal critic of China, said that although he was not out to offend, he would not refrain from speaking up if he felt it was necessary.
"If such right and proper words are considered to be against their law, I will endure all the suing, trials and arrests," he said.
"Numerous predecessors have endured similarly. We have seen how God has always helped them."