Industry groups have warned that the government's proposals to increase the voting threshold on executive pay risk creating "activist minorities" of shareholders.
The Treasury select committee has launched an inquiry into corporate governance in the UK.
Responsible investment group FairPensions has launched a campaign to give the public a say on spiralling executive pay, amid growing anger on runaway bonuses.
Barclays has announced a surge in profits by over a fifth in the first quarter of 2012, ahead of an expected shareholder rebellion over executive pay.
The National Association of Pension Funds has added its voice to growing shareholder opposition to Barclays' pay packages.
The "old boys network" that makes up the committees which set executive pay must end, a think tank says.
F&C voted down one-fifth of pay packages worldwide in 2011, almost double the amount from the previous year.
Pension funds should engage directly with companies on executive pay, Hermes Equity Ownership Services and the National Association of Pension Funds say.
A leading Labour MP will today call for a reinterpretation of fiduciary duty and dismiss the government's plans to give shareholders a binding vote on executive pay.
Campaigning groups have welcomed the government's move to tackle spiralling executive pay, but warn giving shareholders a binding vote is not enough to stall the practice.