HSBC has issued its starkest warning that UK banks will shift their headquarters from the country if a UK government advisory group proposes that large banking groups be broken up in a move to reform the financial system, the Financial Times said.

The UK government-appointed Commission on Banking is examining ideas on how to prevent a repeat of the banking crisis and one idea – already partly embraced by the US administration of Barack Obama and signed into law – is to split the risky, trading functions of banks from their deposit-taking, retail functions.

Stuart Gulliver, the group’s investment banking head and the favourite to succeed Michael Geoghegan as chief executive, was quoted by the FT as saying that he was “genuinely concerned” that the commission would recommend that universal banks, such as HSBC, should split their high street banking from their riskier investment banking activities.

“It is clearly possible that that commission comes up with a recommendation to break up the banks,” Mr Gulliver said at a conference. “[That] has significant implications clearly for where we may choose to headquarter our institution.”

In January, HSBC moved its chief executive’s office to Hong Kong but the bank has consistently denied it wants to shift its HQ.

The story adds to speculation that a number of London-headquartered banks, such as Standard Chartered, might move HQs from London to the Far East, in part because the centre of economic gravity is seen as shifting there. Other reasons cited for a possible exodus from London include the recent tax rises on high earners, a move seen benefiting rival financial centres to London, such as Zurich, Singapore and Hong Kong.