INVESTORS fired a warning shot at Marks & Spencer chief executive Marc Bolland as the retailer posted its eighth consecutive like-for-like fall in clothing sales.

The former chief of supermarket chain Wm Morrison was re-elected with 95.53% support, while his board colleagues all mustered more than 98% backing from investors gathered at Wembley Stadium for M&S's annual meeting.

The Dutchman's future remains in doubt after it posted a 1.6% fall in like-for-like sales of general merchandise for the 13 weeks to the end of June.

Mr Bolland said: "We see some progress in general merchandise, not enough though. I am not yet happy."

At least one bookmaker lists him as its favourite to be the next retail chief executive to leave.

Since taking over in 2010, Mr Bolland has focused on overhauling M&S's back office infrastructure and revamping stores.

But one shareholder complained of "bog standard" clothing lines.

"It is this failure over more than two years in the home markets that has led to the eighth consecutive announcement of dismal quarterly progress," he told the meeting.

Another asked: "How long are we supposed to wait until we see results?"

Private investor John Farmer said: "Year after year we get excuses, we get pleas for more time."

Chairman Robert Swannell said: "It is very exciting to be part of M&S at a time when we are transforming this business to be modern and fully equipped and prepared for future growth."

The former chairman of music retailer HMV said: "We are not here for a popularity contest. We are here to make the right decisions for the long term."

He praised the "considerable achievements" of M&S's management team led by Mr Bolland.

But he drew criticism for the decision to award Mr Bolland a bonus for last year, boosting his pay by 25% to £829,000.

"Every pound of the bonus that was allocated to Marc and the team... was wholly justified," Mr Swannell said.

Nevertheless, the mood in the room suggested most investors are prepared to give M&S's bosses a little more time to turn around the company despite two years in a row of falling profits.

Support was offered by Ian Greenwood, chairman of the Local Authority Pension Fund Forum (LAPFF), who attacked the "chattering classes" and short-term investors critical of the company's turnaround proposals.

"We have confidence in the plan," he said of the group of 46 council pension funds.

It is older Middle Britain – 75% of M&S's sales go to those aged over 45 – that will determine if M&S's autumn and winter range, which will be released into stores on July 25, is the success the company so badly needs.

M&S style director Belinda Earl, who joined 10 months ago to stop the slide in market share in key categories such as womenswear, sought to convince them of the increased quality and style of its range.

As models paraded items from its latest offering on a stage adjacent to the directors' table, the former Debenhams chief executive said she has been "in listen mode" and highlighted M&S's decision to put sleeves on 90% of its dresses.