FANS have called for heads to roll after the Rangers board admitted the club's financial future will be uncertain if a bid to raise £3.6 million ends in failure.

The board of Rangers International Football Club plc has admitted it will be unable to pay the club's creditors if the plan to sell off 19.8 million shares in the operating company is unsuccessful.

The directors told the Stock Exchange they hoped the funding would help "rebuild and re-establish Rangers as a stable, sustainable and successful business". It comes against a background of dropping attendances and declining revenues as thousands of fans vote with their feet in the dispute over the way the club has been run.

Rangers supporters coalition group The Union of Fans (UoF), backed by former Rangers director Dave King, began a campaign to have season ticket money withheld last April until there were irrevocable assurances about the future of Ibrox and the Murray Park training centre.

The board admitted that if the new share take-up is less than the minimum set at 15 million "the future of the company will be uncertain". The directors would have to seek emergency financing "which may or may not be available". The declaration has angered fans who fear a second insolvency in two-and-a-half years.

Chief executive Graham Wallace said in April in delivering his 120-day business review there was "no threat" of a second administration. His review said the club had "mismanaged almost all of its cash reserves" and though it had raised £70m since May 2012, by December 2013 it had just £3.5m left.

It is understood an offer by Mr King remains on the table to reinvest £30m in the club in exchange for a fresh shareholding in RIFC plc.

The club admitted funds raised will be used in part to pay off a £1.5m loan from shareholders Sandy Easdale and George Letham secured in February, due to be repaid by Monday. That cash was raised to tide the club over until season-ticket renewal fees started ­arriving at the end of last season.

Rangers Supporters Association general secretary Drew Roberton said: "I think some people's positions are becoming rapidly untenable. If they are suggesting if they can't raise the money they cannot pay the creditors then what credibility has the man that said administration is not an option got left? It smacks also of the same short-termism they criticised the previous regime for.

"There are people like Dave King who have approached this board with a view to putting money in. Why are they not willing to deal with these people?"

The UoF said fans and shareholders should not be "blackmailed" into servicing the board while the threat of a second administration hangs over the fans and shareholders with money raised only being used to repay loans, to pay fees and to pay bills. "The claim that this money will be used to 're-build and re-establish Rangers is false. It will only serve to keep an incompetent board in place for a few more months."

The group asked the directors to "finally do the right thing" and gain shareholder approval for "significant, much-needed investment and allow those who care about Rangers to take it back to where it belongs".

Earlier this month, an attempt to raise £10m from city investors was unsuccessful, prompting yesterday morning's open offer.

The new ordinary shares are priced at 20p each, marking a 21.6 per cent reduction on the club's most recent closing price of 25.5 per cent, which Rangers hope will encourage uptake.

Rangers manager Ally McCoist threatened to walk out of his pre-match press conference yesterday while repeatedly refusing to discuss the club's finances after plans for the new share issue were revealed.