A set of Nisa shopkeepers are hoping to block a takeover of the business by the Co-operative Group.
The Co-op made an offer to buy convenience store Nisa for £137.5m last month, with the board unanimously voting in favour of the deal.
The shopkeepers will vote on the merger on 13 November. More than half of Nisa members will have to approve the deal for it to go through.
However, the Times reports that a group of Nisa members is taking legal advice on how to block the deal, saying that it favours smaller shareholders.
Nisa members will each receive a £20,000 payment when the deal is completed. And, over the next four years, payments totalling £137.5m will be handed out to members.
A Nisa spokesperson said: “The feedback from recent shareholder meetings suggests growing support for the Co-op’s offer.
“Many convenience retailers are struggling against significant headwinds from the minimum wage, dark tobacco, Brexit, rising rents, and the entrance of larger competition into convenience. There is growing demand for a tie up that provides greater buying power, an enhanced range, better fresh and chilled, and lower cost prices."