The board of HSBC has "full confidence" in its chairman Douglas Flint the bank's senior non-executive told shareholders yesterday as they questioned recent scandals and recorded a significant 24per cent vote against the remuneration report.

Simon Robertson said the bank's board stood united behind Glaswegian Mr Flint and his chief executive Stuart Gulliver as "the people who we are trusting to help us through the problems we have and we will hold them to account".

A shareholder had asked whether the senior heads should roll over the Swiss private bank tax evasion scandal, for which Mr Flint apologised to the meeting.

The chairman said: "Our reputation has been damaged and the financial burden of the unacceptable behaviour has been borne by you, our shareholders in fines, penalties, additional costs and the opportunity costs arising from diversion of management time - this is clearly wrong."

He defended the bank's executive pay policy, saying it had been approved with the support of over 76per cent of shareholder votes.

Mr Flint also signalled that the Tories' intended referendum on the EU and Labour's proposed continuing squeeze on banks would both be bad for business, as he announced a formal review into whether it would remain headquartered in the UK.

He told shareholders that HSBC, Europe's biggest bank, needed to take into account the requirement of UK regulators for it to separate its UK retail business from the rest of the group by 2019.

HSBC is also expected to pay $1.5 billion (£1bn), or about 7 percent of expected profits, under this year's bank levy - which Labour is committed to increasing. That charge is up from $1.1 billion (£730m) last year and almost double the previous year.

The chairman said the board had "asked management to commence work to look at where the best place is for HSBC to be headquartered in this new environment".

Mr Flint went on: "The question is a complex one and it is too soon to say how long this will take or what the conclusion will be; but the work is underway."

Institutional shareholders have been urging HSBC to consider moving back to its former Hong Kong home. One commented yesterday: "This is more than just sabre-rattling, they clearly want the establishment to know that HSBC doesn't necessarily belong here."

But Hugh Young, global head of equities at Aberdeen Asset Management, one of HSBC's top 10 investors, said moving domicile would be a big decision.

"No one should be under any illusion that it's as simple as moving a brass plate from one city to another. It is far more complex than that and involves local, regional and global regulatory frameworks, costs and the future strategic shape of HSBC," he said.

Last week Mr Young said Standard Chartered, where Aberdeen is also a major shareholder, had a much easier decision to make on its headquarters, as unlike HSBC it did not have strong UK and European connections but did have a major franchise in Singapore.

Standard Chartered has said it is keeping domicile under review and has no current plans to move, but is "listening very carefully" to shareholders.

HSBC shares gained 3.6 per cent in immediate trading after the chairman's statement was released, as the market responded to a potential lowering of the bank's costs. "Any such move could lessen their burden in terms of levies and additional taxes that have been applied to the UK banks," said Keith Bowman, equity analyst at Hargreaves Lansdown.

The Hong Kong Monetary Authority said the bank was " the largest bank in Hong Kong and has deep historical links with Hong Kong".

But analysts say moving to Hong Kong may not necessarily make a huge impact, noting that the costs of relocation, and Chinese regulation, would have to be set against lower UK taxes.

HSBC began life in Hong Kong 150 years ago, and has made $24 billion (£16bn) in profits there over the last three years, compared with a $4 billion (£2.6bn) loss in the UK over the same period.

It moved from Hong Kong to London in 1993 when it bought Midland Bank.