Lifelong United fan Keith Harris, the former chairman of the Football League and executive chairman of investment bank Seymour Pierce, says raising the money to purchase the club "is the easy part" but convincing the owners to sell was much harder.
As the club's debts have swelled to 716.5 million pounds, increasing numbers of fans are shunning the side's red and white colours and attending matches in green and gold, worn when the team were known as Newton Heath in its early days.
The protest has attracted thousands of followers and Harris says fans must now start boycotting matches if they wanted to force the Glazer family to sell.
Harris started to organise a possible takeover after being contacted by members of the Manchester United Supporters Trust, whose membership has risen to 50,000 in recent weeks.
He told the Daily Mail on Tuesday: "It is no good fans turning up 10 minutes late for matches, they have to do more than that.
"The green and gold protest is fabulous, a symbolic and significant message to the owners. Its like white handkerchiefs in Spain but it won't force the Glazers to sell to us.
"If enough people - and I'm talking about thousands - stop turning up to matches and do not renew their (season) tickets then that does it.
LONG-TERM GAIN
"The supporters have to hurt the Glazers in the pockets. They have to be prepared to take the pain of not watching their club in order to achieve long-term gain.
"They have to be galvanised and say 'we will not come, we will not buy programmes and merchandise.'
"It's a big ask, it's a risk, but that is what must happen. The Glazers are thick-skinned and seem impervious to protest. They will not be impervious to enormous drops in revenue."
He said he would not have made news of a possible takeover public last month if he was not serious.
"I would not talk about this if I didn't have full confidence in our ability to raise the money to do this.
"Getting the money together is the easy bit. But we can't make an offer until the Glazers are placed in a position where they are forced to consider it."
The Manchester Evening News reported on Tuesday that in an unthinkable "unholy alliance" the fans of arch-rivals Manchester United and Liverpool would stage a joint protest against their North American owners when they meet at Old Trafford next month.
While United fans are unhappy with the Glazer family owning their club, Liverpool fans have been increasingly protesting against their owners Tom Hicks and George Gillett.
A representative for the Glazers was not immediately available for comment.
