Last week, the Association of British Insurers (ABI) warned WPP investors to carefully examine the new remuneration scheme ahead of the shareholder vote today in Dublin.
However, The Times reports today that the package will now likely be approved, although a quarter of investors are expected to rebel.
A precedent for restraint on executive pay was set a week earlier at Royal Dutch Shell after more than half of shareholders rejected the company's latest remuneration report.
With the onset of the recession, increased shareholder scrutiny also caused the veto of similar schemes at RBS and Provident Financial.
WPP investors now believe its incentive plan will be pushed ahead by leaning on its American investors, who own 38% of the company, to overcome any shareholder rebellion.
The scheme would allow Sorrell to earn a possible £60m in bonuses over the next five years if WPP outperforms against a group of nine companies, including Omnicom and Publicis, during that period.
Under the scheme, Sorrell could potentially invest $19m (£12.5m) in the company spread over five years to be eligible for the maximum payout, up to five times his investment or $95m (£60m).
WPP said the incentives package, known as Leap III (Leadership Equity Acquisition Plan), is fair as it requires executives to invest in the company and that payouts are determined by the company's overall performance.
It is the third incentive plan in the past decade at WPP and a more generous replacement than the last scheme which began in 2004 and started to pay out this year.
The 2004 Leap plan was approved by 80% of WPP shareholders, with 15% opposed and 5% declining to vote.