Vodafone boss Arun Sarin is set to face a shareholder revolt at group's annual general meeting this week, reports say.
Mr Sarin will have to face angry investors on Tuesday
A significant number of investors are expected to vote against re-electing Mr Sarin to the mobile phone giant's board, the Sunday Times said.
Investors are unhappy with its recent performance, which has cut its share price to 111.25p from 150p in November.
In May it said losses had increased to £14.9bn and last year warned rising competition would cut its revenues.
Investors holding 10% of the firm are expected to vote against Mr Sarin's re-appointment, a move the Sunday Times said represented an "unprecedented" level of opposition for a UK firm.
On Friday, Morley Fund Management, which owns a 2% stake in the company worth more than £1bn, confirmed it would be voting against Mr Sarin.
Reports claim fellow fund manager Hermes and Standard Life could also join Morley in a protest vote at Tuesday's meeting.
Investors are also widely expected to vote against proposals for a shake-up of executive bonuses which would lower targets and so make it easier for them to earn rewards.
Vodafone's future prospects have been hit by stiff competition in the mobile phone market, falling call tariffs and the recent EU decision to cap roaming charges.
Meanwhile in May, it revealed a record-breaking £4.8bn loss after it incurred one-off costs of more than £23.5bn.
The loss was related to the revaluation of its German business Mannesmann, which it bought in 2000 for £112bn ($183bn at the time).