Some 26.9% of Barclays shareholders have voted against the bank's executive pay awards for 2011 after its chairman was forced to apologise to quell investor anger.
Despite the sizeable mutiny, the majority of investors (73.1%) approved the remuneration report, which includes a total pay and bonus award of £25m for Barclays chief executive Bob Diamond.
Barclays chairman Margus Agius had earlier apologised to shareholders in an attempt to head off the revolt over the bank's bumper pay packages for its bosses, which are now set to go ahead despite Mr Diamond admitting the bank's performance was "unacceptable" last year.
While the massive protest vote will come as a sting to Barclays management, shareholder votes on pay are not binding so the bank's board would not have been obliged to act even if a majority voted no.
Speaking at the bank's AGM in London ahead of the vote, Mr Agius said he was sorry for for badly communicating the bank's pay policy and promised higher dividends in future.
The row erupted after the Association of British Insurers and the shareholder representative group PIRC urged their members to vote against the bank's 2011 remuneration report.
Investors are unhappy at the multi-million pound bonuses being handed out to Mr Diamond and other executives in the face of a relatively poor performance and comparatively low dividends.
Barclays argues that it operates in a competitive industry so needs to pay such rewards to recruit and retain the best staff, and that it should not be subject to the same scrutiny as banks that received state bail-outs.
Mr Agius's speech to hundreds of shareholders at London's Royal Festival Hall was interrupted by occasional heckling and laughter, although the occasion was not as stormy as expected.
Kicking off the AGM ahead of the shareholder vote, he said: "We recognise the importance to you of dividend income and this is a key factor in the way we plan for our future growth.
"Evidently, we have not done a good enough job in articulating our case.
"For this I apologise and I assure you that in the future we will be engaging differently and more purposefully with shareholders in order to ensure that we obtain a broader level of support on remuneration policy and practice."
Despite this, Mr Agius said "the brutal reality" was that paying "zero bonus" was not an option.
Mr Diamond followed the chairman and started by hailing the bank's first-quarter results , published on Thursday.
The bank recorded a 22% rise in underlying pre-tax profits to £2.4bn, driven by a strong performance at its UK retail arm.
Turning to pay, Mr Diamond said: "We recognise the shareholder concerns and
we're committed to making further progress."
The American banker last week tried to quell shareholder anger by offering to only take half of his £2.7m all-shares bonus for 2011 if certain performance targets are not met within three years.
A £5.7m tax payment made by Barclays on Mr Diamond's behalf when he moved from the US to London to take up the role has also sparked anger among investor groups.
Alison Carnwath, the bank's remuneration committee chair, was also taunted and booed when she took to the stage to defend Barclays' decisions on pay.
Introducing herself as "the new girl on the block", she said: "We reduced awards significantly in 2011.
"We will continue to seek to push down remuneration levels in the context of the environment in which we operate."
PIRC also called on shareholders not to re-elect Ms Carnwath as chair of the bank's remuneration committee.
In the event, 20.84% of shareholders voted against her re-election.
The Institute of Directors (IoD) has raised concerns over the growing gap between rewards for senior management and profits shared with shareholders.
Its director general, Simon Walker, told Jeff Randall Live : "At the moment Barclays is paying three times more in bonuses to top executives as it pays in total dividends to all shareholders which is basically the pensioners of this country.
"We think that needs to tilt back to the kind of balance that it had a few years ago."
However, there are plans within Government to give shareholders the final say on executive pay.
Lord Oakeshott, the former Liberal Democrat Treasury spokesman who resigned after criticising the Government's attempts to curb bonuses, welcomed the shareholder backlash.
He told Sky News: "We have had apologies from Bob Diamond and Barclays before but what we need is behaviour change.
"They have been helping themselves before shareholders and customers for far too long and that has got to change."
Shadow business secretary Chuka Umunna said he was "incredibly encouraged" to see shareholders and investors taking such an interest in the bank's pay policies.
Unlike rival banks RBS and Lloyds Banking Group , Barclays did not receive a taxpayer bailout during the 2008 financial crisis.
However, Barclays has benefitted from the Government's underwriting of the entire financial system.
Yesterday, Barclays announced it was putting aside an additional £300m to pay as compensation for mis-selling payment protection insurance (PPI) after a spike in claims, taking its total bill to £1.3bn.
When pressed on the matter at the AGM, Mr Diamond said mistakes had been taken into account.
He said: "The impact of PPI has impacted remuneration.
"There is no-one employed at Barclays today that was part of the management decisions that led to PPI."