Murray said on Friday that Ticketus, whose money allowed Craig Whyte to complete his takeover, were backing his consortium along with the main supporters’ groups.
On Sunday Murray revealed that motoring tycoon Douglas Park was among those who have expressed interest in his group, along with two London-based businessmen - fund manager John Bennett of the Henderson Group and property adviser Scott Murdoch of CWM.
And Johnston - an outspoken critic of Whyte - believes Murray is the right figurehead for the Glasgow giants, currently overseen by administrators Duff and Phelps.
Johnston said: “Paul Murray is working 48 hours a day and he is working against the clock. I have spoken to him almost every day for the past ten months.
“His and his team’s ambition is to see Rangers not only survive, but thrive.
“I have no doubts about his motivation. He is not a man driven by ego.”
On Whyte, Johnston, who opposed the takeover, added: “Do I feel vindicated? Yes. Do I feel any satisfaction? No. The satisfaction must come with the revival of Rangers.
“He (Whyte) is not wholly out of the game, but the barriers to his re-entry are very high.
“I am more hopeful. Whyte is almost out of the door. He is no longer the helmsman taking Rangers on to the rocks. We have to get the club back.”