Rotherham chairman Peter Ruchniewicz has warned the club could fold in weeks if they fail to close a funding gap.
Rotherham need to raise £1m in order to survive
A Save Our Millers campaign has been launched in a last-ditch bid to raise £1m to avoid going out of business.
Ruchniewicz told Rotherham's website: "If we cease trading the club is likely to go straight into liquidation and go out of existence.
"But we believe the club can be saved if anyone with any sort of link to it gets behind us."
Rotherham are currently losing £140,000 a month and Ruchniewicz said: "We're sorry to have to tell fans that the club's financial position has reached a critical phase.
"If the club does cease trading, it is unlikely to go into formal administration given its limited resources and level of funds and assets required.
"The thought of the club going out of existence is too dreadful for any of us to contemplate, but is nevertheless a very real possibility."
Rotherham claim a series of blows have added to the financial woes which existed before the current board took control.
The blows include a poor response to a recent rights issue, a reduction in season tickets sales and declining gate receipts, and an ongoing dispute with Southend over the transfer of Jamal Campbell-Ryce.
Ruchniewicz added: "We're being advised by licenced insolvency practitioners and are in consultation with the Football League on a regular basis to try and find a solution.
"As a board we have statutory duties not to allow the club to trade beyond a point we believe it cannot recover from. That point in time is fast approaching."
As part of its survival appeal, Rotherham have launched two initiatives, £Ten To Play Again, and £Twenty Five To Stay Alive.