Some of the biggest holders of UK stocks plan to get tougher on executive pay, as the UK government turns up the heat over the yawning income gap between bosses and employees.
Doubts remain over whether shareholders will force through many major changes.
Nevertheless, three of the five biggest investors in companies on the FTSE 350 index have set out fresh guidance on setting top pay, or say they plan to do so before votes at annual general meetings this spring.
Fund managers typically worry about how incentive schemes will encourage executives to achieve better returns for shareholders.
They do not necessarily worry about the amount the bosses take home - the often startling sums which grab headlines.
So far, investors have had little public success in forcing company boards to change executive pay arrangements by accepting their guidance, and often their complaints about excessive handouts have fallen on deaf ears.
But now, with British Prime Minister Theresa May championing those workers who are struggling to get by, more is at stake.
The fund arm of insurer Legal & General, the number two investor in FTSE 350 stocks, issued new guidance last autumn and says it will not be alone in holding firms to greater account.
According to the High Pay Centre, a campaign group, the median annual pay of bosses at the 100 biggest London-listed companies stands at just under £4m.
It declared January 4 as "Fat Cat Wednesday 2017", estimating that by midday, chief executives had already earned more than the average British worker will make all year - £28,200.
Criticism of "Fat Cats" goes back decades but last June's EU referendum in the UK exposed a deep divide between those at the top of corporate and political life, and the wider public.
Highlighting this resentment, May has proposed reforms to curb excessive pay and improve accountability to shareholders.
"It is essential for business to demonstrate leadership - to show that, in this globalised world, everyone is playing by the same rules, and that the benefits of economic success are there for all our citizens," she told the World Economic Forum in Davos last week.
US fund manager Blackrock - which holds around $1.6 trillion of UK stocks and is the biggest investor in the FTSE 350 - warned last week it would vote against boards which failed to meet its new guidelines on pay policy.
These include ensuring that executives' pay rises no more than salaries of the workers they employ, and that it is linked to long-term performance.
The High Pay Centre reported a 10% increase in chief executives' pay in 2015, far outstripping the 2.4% growth of British average earnings.
Norges Bank Investment Management - the investment arm of Norway's sovereign wealth fund and the fourth-biggest FTSE 350 investor, told Reuters it also expects to issue fresh guidelines in the coming weeks.
Vanguard Group, the third-biggest investor, and Capital Group, the fifth-biggest, said they were both reviewing their plans.
The smaller M&G Investments published pay guidelines for the for the first time in November.
The two main types of pay votes at AGMs are on executive remuneration for the previous year, held annually and which are non-binding, and on the policy framework to be used in setting future pay.
These policy votes must be held at least every three years, and have been binding since 2014.
While some companies have updated their policies since 2014, most have waited for the triennial vote to come round again and are therefore planning to do so this year.
Investors have scored some symbolic victories. For example, they rejected a $20m pay deal for BP chief executive Bob Dudley, but the vote was non-binding.
Last year 42 companies in the FTSE 350 had more than 20% of their shareholders vote against either executive pay or the policy for setting it. However, few changes have since been announced to their managements' pay arrangements.
Weir Group did lose a binding vote on its pay policy and was forced to abandon a change that would have lowered the maximum payout to senior management but removed performance criteria.
Along with BP, Smith & Nephew and Paysafe Group also lost non-binding votes on 2015 pay and said they would consult shareholders on the matter.
Anglo American, Babcock International and others flagged their intention to set out new plans at AGMs this year to be put to shareholders.
UK bosses' total pay dipped slightly in 2015 but company earnings fell more, meaning they took home a bigger slice of profits, continuing a decade-long trend.
