MPs hit out at HSBC on Thursday after the bank indicated support for a controversial new law that critics say would limit freedoms for the city’s citizens.

Neil O’Brien, the Conservative MP for Harborough, Oadby and Wigston, said that the bank had stabbed protesters in the back, and called on people to consider switching their accounts.

“If you bank with HSBC you are with a bank that is backing Beijing’s repressive new security laws, designed to snuff out freedom in Hong Kong. Other banks are available,” he said in a post on Twitter.

It came after Peter Wong, HSBC’s chief executive in the Asia-Pacific region, signed a petition in favour of the new law which bans insults to the Chinese national anthem.

If you bank with HSBC you are with a bank that is backing Beijing's repressive new security laws, designed to snuff out freedom in Hong Kong. Other banks are available

It came as fellow Hong-Kong listed bank Standard Chartered also came out in favour of the controversial new bill.

Tom Tugendhat, the Conservative member for Tonbridge and Malling, said: “I wonder why HSBC and [Standard Chartered] are choosing to back an authoritarian state’s repression of liberties and undermining of the rule of law? Where does this fit in their definition of corporate social responsibility?”

In a statement, HSBC said: “We respect and support laws and regulations that will enable [Hong Kong] to recover and rebuild the economy and, at the same time, maintain the principle of ‘one country two systems’.”

Standard Chartered said: “We believe the national security law can help maintain the long-term economic and social stability of Hong Kong. The ‘one country, two systems’ principle is core to the future success of Hong Kong and has always been the bedrock of the business community’s confidence.

“We hope greater clarity on the final legislative provisions will enable Hong Kong to maintain economic and social stability. We remain positive that Hong Kong will continue playing a key role as an international financial hub and Standard Chartered is committed to contributing to its continued success.”

We respect and support laws and regulations that will enable (Hong Kong) to recover and rebuild the economy and, at the same time, maintain the principle of ‘one country two systems’

But investors did not seem overly worried about the news, with shares in HSBC trading down a mere 0.7% in London on Thursday morning.

Experts said that investors were presumably relieved that the bank would not lose access to China, where it makes a large portion of its revenue.

“We can all act shocked and damn them for supping with the devil, but neither bank had any real choice but to make the unpalatable decision to support the unsupportable,” said Bill Blain, market strategist at Shard Capital.

“Both know their futures depend too much on China’s patronage to survive without kowtowing. However, they have written the first lines of the final few paragraphs of their own obituaries. Banks that are run to appease regulators and flatter Governments are unlikely to thrive.”

He added: “Read the comments following any article about the two Hong Kong banks this morning and are they full of earnest virtue signalling from angry clients who say they will close their accounts. I will probably switch mine.. but only because now there is zero chance the service will get any better.”

In response to HSCB and Standard Chartered’s statements, Downing Street insisted that China risked breaching an international treaty unless it changed course.

The Prime Minister’s official spokesman said: “We have made our position very clear.

“If China proceeds with this security legislation this would be in direct conflict with its obligations under the joint declaration, a legally-binding treaty registered with the United Nations.

“Our message is clear and it is shared by our international partners.

“We are deeply concerned about China’s plans to impose national security legislation on Hong Kong and have urged them to reconsider.”