RANGERS' second-biggest shareholder, Dave King, could become the driving force behind the Blue Knights' bid to take control of the crisis-torn club.

The controversial South Africa-based venture capitalist wants to help the initiative, launched last week by former Ibrox director Paul Murray.

Sources last night said Mr King, who owns 5% of Rangers, was ''very anxious'' to help Mr Murray form a viable bid for the club that entered administration last week.

In another development last night, Rangers' ex-chairman Alastair Johnston urged the club's administrators Duff and Phelps to look at the details of Craig Whyte's takeover of the club last year to see if he had subsequently breached any of the terms.

He said any such breach could invalidate Whyte's status as a secured creditor. In a letter, Mr Johnston highlighted former owner Sir David Murray's concerns about whether Whyte had met his obligations with last May's takeover. He wrote that if had there been a breach "then the options for charting a course for reconstitution of Rangers Football Club will be much more readily identifiable".

Mr King was in Glasgow yesterday for talks with Duff and Phelps.

Manager Ally McCoist also met the administrators at Ibrox, before leaving in a car with Glasgow-born Mr King.

A spokesman for Duff and Phelps, said: "Mr King met members of the administration team to discuss the general situation the club is in and his continuing obligations as a director while the club is in administration."

The businessman, who is involved in a long-running tax dispute with the South African authorities that could leave him with a £60 million bill, is the only survivor from Sir David era on the club's board.

He had talks last night with Blue Knights mastermind Mr Murray – no relation of the former owner – who will meet administrators tomorrow.

Mr Murray said later: "There's a lot of things happening but we cannot comment at the moment."

Mr King and Mr Murray have twice been linked in attempts by non-executive directors to buy out the club. They put forward a rival takeover bid to Whyte's in April, and were connected to another takeover bid in 2009.

The Herald understands one of the sticking points over a previous bid was about who would be responsible for footing the bill in the main tax case, which could cost the club £49m.

If Rangers get a Company Voluntary Arrangement (CVA), their creditors, including HMRC, would only receive a fraction of the funds owed.

There was no comment from Rangers or the administrators on the latest talks as officials continue to probe the financial dealings surrounding Whyte's takeover and subsequent running of the club.

Andy Kerr, president of the Rangers Supporters Assembly, believed there would be support for Mr King's involvement. He added: "He's put a fair deal of investment in before and probably hasn't seen much return."

It came as the administrators gave an indication of the plight of the club when they issued a statement last night calling for support from the fans to keep money coming in.

There have been concerns about revenue streams drying up with Rangers out of both domestic cup competitions and money from league matches largely tied up in season tickets that have already been mortgaged to Ticketus.

David Whitehouse, of Duff and Phelps, last night called on fans to make every home match a sell-out, adding: ''It is quite simple. Income now will help secure the future of Rangers.''

Mr Whitehouse added: ''On a daily basis we are talking to department heads and seeing where there is capacity for cost savings but being very mindful of the need to preserve the performance on the pitch and retain the efficiency of the club off the pitch.''

Meanwhile, the three main Rangers supporters' organisations have launched a website www.saverangers.com, where fans can pledge how much money they would be willing to invest.

The Rangers Supporters Association, the Rangers Supporters Assembly and the Rangers Supporters Trust want to know how much cash could be raised if an opportunity for "meaningful fan ownership" occurs.

Meanwhile, HMRC refuted a claim by Whyte on Tuesday that the club was being treated unfairly.