Leung – a vice-chairman of the National Committee of the Chinese People's Political Consultative Conference (CPPCC) – wrote in a Facebook post today that "it has been more than a week and HSBC has not yet expressed its position on the national security law".
He made the comments after the UK, US, Australia and Canada issued a joint statement yesterday expressing "concerns" over Beijing's future national security law for Hong Kong.
According to RTHK, Leung said the joint statement interfered in China's internal affairs, and that "we must clearly show these countries that Hong Kong is not their colony".
Hong Kong was ruled by the British from 1841 until July 1997
"HSBC’s profits mainly come from China, but the board of directors and senior management are almost all British," he wrote.
HSBC was founded by British businessmen in 1865 as The Hong Kong and Shanghai Banking Corporation. HSBC Holdings has been headquartered in London since 1991.
"In terms of political issues, this self-proclaimed British bank can't make money from China while following other Western countries trying to do damage the country's sovereignty, dignity, and the feelings of the people."
He argued that much of the business HSBC does in China can be replaced overnight by mainland banks or banks from other countries.
Leung, who was Hong Kong's chief executive between July 2012 and June 2017, wrote that anyone with HSBC bank accounts – especially deputies to the National People's Congress (NPC), members of the CPPCC, and Hong Kong government officials – should "protect themselves immediately and avoid becoming hostages like Huawei", the Shenzhen-based IT giant shunned by the US and other Western countries.
Leung ended his message by saying: "We need to let British agencies like the British government, politicians, and HSBC know which side of their bread is buttered".
He also took aim at the US government's announcement that sanctions may be imposed on China if the national security law is passed, saying "we need to fight back".
The NPC passed a decision in Beijing on Thursday giving a green light to its Standing Committee to draft national security legislation for Hong Kong.
Leung also criticised comments made by former governor of Hong Kong Chris Patten, who said that "China is an enemy to us now" and "China must pay a price."
Patten was Hong Kong's last London-appointed governor, from 1992 to 1997.
In reply, Leung wrote: "I want to tell the British that China will also draw a line in the sand, and see who pays the price."