Alisher Usmanov fears the "pinnacle" of Arsenal's ambitions next season will be just securing Champions League qualification again, as the Gunners face up to the prospect of seeing captain Robin van Persie leave.
Red & White Securities Limited, fronted by Usbek oil magnate Usmanov and Farhad Moshiri, hold around 30 per cent of shares in the Gunners' parent company, which was the subject of a takeover in 2011 by American tycoon Stan Kroenke.
Usmanov, who does not have representation on the board, insists RWS will to continue the acquisition of stock - which currently is trading around a £17,000-high per share - and maintained pressure would also be brought to try to drive the club towards being able to deliver sustained success on the pitch once again.
His letter read: "You can try and put a good face on a bad game for as long as you want, pontificating about the merits of this model, but it will not hide the obvious fact that it just does not allow our great manager to fully realise his managerial talent and deliver success for the fans who are paying the highest prices in the land.
"It appears that a place in the Champions League will be the pinnacle of our ambition again next season. Unfortunately, in the future we may see this ambition lowered further."
The claims by RWS follow on from the announcement by Van Persie, in a carefully worded statement on his official website, that he would not be extending his current deal, which runs out next summer.
RWS maintain it is a situation which should never have allowed to transpire, as it did last summer with the sale of first former captain Cesc Fabregas to Barcelona and then playmaker Samir Nasri to Manchester City.
"This policy is leading to the loss of our best players, often to our main competitors, and even causes the players themselves to question their future at the club and the club's ambitions. The situation with our captain and outstanding performer from last season Robin van Persie sums this up," the letter continued.
"Yet again we are faced with losing our true marquee player at the club because we cannot assure him of the future direction and give confidence that we can win trophies. Where are the safeguards to ensure that this doesn't happen again and again in the future?
"As a top club we should, at the very least, match if not beat the offers that other clubs make to try and lure our very best players away, and also provide a more compelling vision of the future Arsenal will take time reviewing statements of the open letter before deciding whether to make any official response."