The top two directors of troubled photo booth operator Photo-Me International have agreed to step down from their posts under pressure from shareholders.
The future of Photo-Me's kiosks' business is key to its outlook
Vernon Sankey, the firm's chairman, will not seek re-election at its October AGM while chief executive Serge Crasnianski said he would retire early.
But two key investors said resignation alone would not address wider concerns about how the firm was being run.
Frustration over Photo-Me's management has been bubbling for some time.
Investment company Principle Capital and hedge fund Cycladic, which together own 18.2% of the Surrey-based company, have been increasingly unhappy with the way Photo-Me's business has been run.
Cycladic and Principle Capital said the announcement that Mr Sankey and Mr Crasnianski would step down "fails to address shareholders' concerns about the leadership", at a time when the board of directors would need to make key decisions regarding the company's strategy.
Backed by 50.4% of shareholders, Cycladic and Principle Capital "urge Vernon Sankey and Serge Cransianski to resign immediately from the board".
They argued that this would eliminate the need for an extraordinary general meeting (EGM), allow the strategic review process to go ahead smoothly and allow the board to make a decision about the sale of the vending division with the shareholders' approval.
They have accused Mr Sankey and Mr Crasnianski of "operational mismanagement" and noted a "long history of poorly managing investor expectations".
The investors have been threatening to hold an extraordinary general meeting where they said they would have the support of more than 50% of the firm's shareholders to oust the bosses with immediate effect.
But Photo-Me has insisted that an EGM would "jeopardise" the vending division disposal, which - if successful - would return a significant amount of capital to shareholders.
Profits have taken a beating over the past few years as the ease with which digital photographs can be distributed electronically now means there is less demand for photographic prints.
The company has been looking to sell its core vending business, which is responsible for photo booths and the media kiosks which process prints from digital cameras and phones.
But Principle Capital and Cycladic said they felt that progress with the sale and other aspects of a strategic review launched last year was insufficient.
Meanwhile, the firm said its was unanimous in its belief that the continuation of the vending division disposal process was the right one at the moment.
He added that the management changes "must be smoothly managed to avoid further unnecessary and damaging disruption to the business".