Stephen Hester, the chief executive of RSA, the London-based insurance group behind the More Than brand, was last year handed a total pay and benefits package of more than £4m. The 58-year-old received a basic salary of more than £1m, a bonus of £800,000 and a longer-term incentive payout of nearly £2.2m. He was given a car and driver, worth £64,000. And an extra £302,000 to help him “save for retirement”.

That level of pension contribution – 30% of basic salary, usually paid in cash – is far from unusual in top company boardrooms. Many directors get more. But the cash handouts are fast becoming the focus of shareholder anger, as investors increasingly question why the best-paid bosses get far higher contributions than workers.

Hester’s 30%, for instance, compares with contributions of 9-11% for RSA staff. The yawning gap is set to be one of the key issues of this year’s AGM season, when shareholders get the chance to question pay policies – and vote against those they think are too generous. Currently, 45 of the companies in the FTSE 100 index offer annual “contributions” – usually cash handouts – equal to 25% or more of their chief executive’s basic salary. Recipients are not obliged to put the cash into a pension. The worst offender is holiday firm Tui, with chief executive Friedrich Joussen getting some 51% of his salary.

The new focus on executive excess – this time in the shape of pension allowances – was prompted by the Investment Association, a trade group that represents fund managers handling £7.7tn in assets. Last November it updated its guidelines and spelled out that companies should “pay pension contributions to directors in line with the rate given to the majority of the workforce, rather than giving higher payments as a mechanism for increasing total remuneration”.

Andrew Ninian, its director of corporate governance, said the revised code has helped the issue gain “widespread traction” among investors. The association has warned firms that it will now give an “amber top” warning on companies that continue to offer executives pension payments worth 25% or more of their salary.

Shareholder advisory group Glass Lewis is also ramping up the pressure. It wants companies to cut contributions for newly appointed executives to 16%. There are signs that the pressure is starting to force change. Last month HSBC’s £4.5m-a year-boss, John Flint, had nearly £250,000 shaved off his total income after shareholder pressure forced the bank to reduce his pension contributions from 30% to 10%. His pension allowance will fall from £372,000 to £124,000. HSBC staff get 9-16%.

British Gas owner Centrica – where RSA’s Hester is the senior non-executive director (for which he gets paid another £92,000 a year) – is to cut its executive pension contributions in half, to 15%. Hester may have taken the hint, because his own contributions are now to be reduced, in stages, to 24% – just below the level at which the Investment Association will protest, but still more than double that of colleagues further down the ranks.

Lloyds Banking Group has cut the pension payout for its chief executive, António Horta-Osório, from 46% to 33%. Mark Brown, general secretary of Lloyds union Affinity, is not impressed. He called the small reduction an “obscene piece of symbolism designed to distract attention away from the fact that he still gets a pension allowance worth 33% of salary, whereas everyone else in the bank gets just 13%”.

Tui, however, seems less concerned with cutting the 51% handed to Joussen. A spokesman said: “Shareholders are in the position to vote against the remuneration system – which includes the pensions. The voting results, however, illustrate that there is currently no great pressure with regards to remuneration including pensions.”

At a glance

FTSE 100 pension contributions

50% or more of salary
Tui 51%

40-50% of salary
CRH 47%, Standard Chartered 40%, Ashtead 40%

30-39% of salary
RBS 35%, WPP 35%, British Land 35%, Lloyds 33%, AstraZeneca 30%, Diageo 30%, Shire 30%, Reckitt Benckiser 30%, National Grid 30%, Anglo American 30%, Ferguson 30%, Intertek 30%, Burberry 30%, Centrica 30%, Segro 30%, Sainsbury’s 30%, RSA Insurance 30%, DS Smith 30%

25-29% of salary
Halma 26%, BHP 25%, Rio Tinto 25%, Prudential 25%, Tesco 25%, Rolls-Royce 25%, LSE 25%, IAG 25%, Whitbread 25%, Mondi 25%, Informa 25%, InterContinental 25%, Bunzl 25%, Rentokil Initial 25%, Land Securities 25%, Johnson Matthey 25%, Smiths Group 25%, Morrison 25%, Barratt 25%, M&S 25%, Severn Trent 25%, Spirax-Sarco 25%

•This article was amended on 2 April 2019 to remove BT, which was incorrectly included in the list above