Ashley, who bought almost 9% of Rangers shares in the initial public offering, has been continually linked with further involvement in the club, though a majority stakeholding would be problematic under UEFA rules if the Ibrox club and Newcastle United were to qualify for European competition.
It is understood that approaches have been made to Ashley from the Ibrox board as the club seeks money to stave off a debilitating crisis. City sources told Herald Sport last week there had been little enthusiasm for participating in such an initiative and Ashley now seems to have emerged as the board's best hope of investment.
But the Union of Fans, an umbrella group of Rangers supporters, last night warned the club over strengthening links with the Newcastle owner. It claimed the Scottish Football Association had been approached to "give clearance" but this could not be confirmed as Scottish football's ruling body is sensitive to making comments about matters that would affect the share price of a member club.
A statement from the Union of Fans read: "We would question the wisdom of approaching someone who, despite his obvious wealth, cannot significantly invest in the club without removing himself from his ownership position at Newcastle.
"Why are the board persisting with these short-term, desperate measures? The club needs urgent, substantial investment - not a short-term fix which will be lucky to see us past Christmas. Even if they are successful in raising the £4m, almost half the money will immediately have to be used to repay overdue loans."
The fans group pointed out that before the annual meeting last year they had been assured that the club could raise such funds "at the push of button".
The supporters are also concerned that Ashley's involvement could cause problems between the Ibrox club and the governing bodies.
The Union of Fans statement read: "Will the board get an unequivocal assurance that the SFA will not use this issue as a stick to beat the club with further down the line? The SFA have a track record of attempting to impose draconian sanctions on Rangers using tenuous methods."
The statement added: "We are also concerned that, under UEFA regulations on dual ownership of clubs, Mr Ashley cannot have a 'decisive influence over decision making' at Rangers without it leading to the possibility of us not being able to compete in European competition."
The fans are also worried that Ashley's involvement may be linked to a growing influence of Charles Green, the former chief executive, who barged back into the Rangers story this month with claims he had investors lined up.
Crucially, the supporters also worry that the naming rights of Ibrox would be part of the deal, allowing Ashley to name the stadium after his Sports Direct business.