The Arsenal Supporters' Trust (AST) has sent a letter to all the club's shareholders asking them to reject Stan Kroenke's offer to buy their shares.
Recently the American sports tycoon submitted documents for a proposed £730m takeover offer for Arsenal.
Kroenke Sports Enterprise holds a near 63% stake in the Gunners giving it a controlling interest.
But it needs to buy the 27% owned by Alisher Usmanov - and shares held by the AST - to complete a full takeover.
Red and White Holdings, the investment vehicle of Russian-based Uzbek billionaire Usmanov, is unwilling to do business over its stake in the club.
Though the AST - whose membership consists of around 1,000 shareholders and supporters - insists it is not against Kroenke's interest in Arsenal, it is opposed to one person having control of the whole club.
"The AST believes that Arsenal is stronger when supporters are represented in its ownership structure," read the letter to 1,500 shareholders.
"This arrangement means we can ask questions at an AGM and scrutinise the official report and accounts, something the AST has gained a reputation for doing with clarity and expertise.
"We also think that having supporters involved in the ownership helps to give the club a real sense of 'belonging' and acts as a check and reminder to those that run the club that its most important asset is its supporters.
"The AST has established a role as a watchdog of the club and there are numerous examples of where we have influenced policy and also ensured that the views of fans are listened to."
Last year the AST set up Arsenal Fanshare, a scheme under which 1,800 fans have bought a small stake in the club totalling an investment of more than £650,000.
Shareholders have until 27 May to decide whether to accept Kroenke's offer.
After Kroenke announced he would mount a takeover bid, the Arsenal Independent Supporters' Association (Aisa) issued a statement urging the American to "take advantage of his opportunity to win over fans".
Aisa wants Kroenke to promise that no debt arising from the purchase of shares will be transferred to the club, and they also called on the Gunners to freeze ticket prices.