A petition launched by the Sons of Struth fans group calling for the Newcastle owner to agree to fairer retail arrangements with Rangers has amassed over 3,000 signatures in eight hours.
The move has come a day after the Rangers board sanctioned a general meeting showdown with Mr Ashley and revealed moves to shift his influence at the club.
The club's board said the meeting, called by Mr Ashley to call in his £5 million loan to the club, will be held at Ibrox on June 12.
The Rangers International Football Club plc board said it wants shareholders at the meeting to support directors to ensure contractual arrangements between the club and Sports Direct are "renegotiated on a basis that is fair and reasonable for both parties and will delivery best value" to both parties.
It has indicated that it wants to reveal to shareholders at the meeting the extent of Mr Ashley's hold over Rangers's merchandising.
Sons of Struth said that all comments posted in the online campaign would be sent to Mr Ashley.
They said: "We would urge (that) no Rangers fan buy any merchandise until a fairer contract is established or cancelled.
"Go now, enough is enough".
The group is concerned over reports that the club gets just 75p out of every £10 spent on merchandise on a seven year rolling contract.
Among those already making their feelings known was David Macdonald who said: "Rangers men for Rangers not some parasitic businessman who only understands money. Get out of our club you are most certainly not wanted."
Brian Ward added: "Rangers fans have suffered enough over the past four seasons, Mike Ashley is rubbing salt in the wounds."
The Rangers board, in agreeing to the showdown meeting with Mr Ashley, said they will provide shareholders with a breakdown of the income received by Rangers Retail Limited since its incorporation and the payments made by RRL to the Club.
It says it will also advise shareholders on certain of the terms of the shareholders agreement relative to RRL and the effect these terms could have if valid and enforceable.
From January 27, the Ashley, who is also Newcastle United owner has been the "ultimate controlling party" of Rangers Retail, which handles the club's merchandising and stores. Papers confirmed the switch has been made from the previous controllers, RIFC plc as one of the conditions of the £5 million loan.
Accounts reveal that while Rangers Retail turnover quadrupled from £1.2 million in the year to April 2013 to £4.8m in the year to April 2014, profits only doubled from £434,312 to £877,662. That is because the costs of the sales soared by eight times that of the previous year from £546,656 to £4.2m.
It is understood most of that money has gone to Sports Direct as Rangers Retail is buying Rangers merchandise, including replica kits, gifts, polo shirts and track suits from the Ashley-controlled firm for use in club outlets.
Sports Direct confirmed that Rangers Retail has provided over £3.8m to Sports Direct in the year through such sales.
When Rangers Retail, a joint venture with Sports Direct, was confirmed by the club under then chief executive Charles Green in August 2012, it was promoted as enabling Rangers "to once again control its retail operation and give supporters the chance to buy direct from the club and in doing so, continue to invest in its future".
Under the previous 10-year retail agreement with JJB struck by Sir David Murray in 2006, Rangers accepted an initial £18m from the sports firm, while it was also guaranteed a minimum royalty fee of £3m per year until 2016.
In the latest set of accounts, published in March, as working capital remained a major issue, £3.2 million relating to Rangers Retail was included in the £3.3 million cash balances of parent company Rangers International Football Club plc.
Rangers Retail runs the club's entire retail operation, including the Rangers Megastore, and hold the rights under licence to the club's famous crests.
Sports Direct have been approached for comment.