Vodafone Group faces a potentially widespread shareholder revolt after one of its biggest investors said it would vote against the re-election of chief executive Arun Sarin.

Morley Fund Management, whose 2.1 per cent stake makes it one of Vodafone's 10 largest investors, plans to vote against Sarin and a number of other directors at the company's annual meeting on Tuesday.

A spokeswoman for the fund declined to elaborate on its reasons.

The shareholder rebellion could be wider than Morley; yesterday, press reports suggested investors controlling 7 percent of Vodafone shares were set to vote against the chief executive.

Next week's annual general meeting comes after months of boardroom upheaval at the mobile telephone giant, with several directors set to step down at the meeting.

Newspapers have reported a rift between a new guard led by Sarin and an old guard that included outgoing chairman Ian MacLaurin and former chief executive Chris Gent, who quit his honorary position as lifetime president of the firm earlier this year.

In recent months, shareholder groups including Manifest, PIRC and the Association of British Insurers have all raised concerns about the lowering of targets that determine executive bonuses. Manifest also questioned the independence of non-executive director Michael Boskin, who is seen as close to Sarin.

"It is not for us to comment on the individual views of our shareholders," a Vodafone spokesman said. "As far as we are aware, the vast majority of votes cast will be in support of the board."

Under Sarin's tenure, Vodafone's revenue growth has begun to slow, causing investors to question its strategy and call for the sale of its stake in the US joint venture Verizon Wireless.

The company is also facing uncertainty on several regulatory issues on roaming charges and international termination rates.It will provide an update of its first-quarter key performance indicators on Monday.