QPR chairman Gianni Paladi has revealed the Rs could fall into administration by the end of the month if a rescue package is not found.
Rangers must pay a £1.3m bill to the Inland Revenue by September 1.
Renault Formula One team boss Flavio Briatore has been linked with a £30million takeover, although QPR Holdings chairman Antonio Caliendo said earlier this week that the club was not for sale.
"There is now a huge concern over the club's future," Paladini told the Daily Telegraph. "Flavio has made it plain that if one decimal point moves on the agreed price, he doesn't want to know.
"There is no-one else ready to step in."