The Scottish Socialist Party is expected to go £200,000 into the red by the end of the current financial year.
Party leader Tommy Sheridan appealed to supporters to help
Leader Tommy Sheridan conceded that the party faced "a potential deficit" but he stressed that the SSP does not face financial meltdown.
"We are determined that we will come through this even stronger," said Glasgow MSP Mr Sheridan.
He also confirmed that he and Rosemary Byrne, a fellow SSP MSP, had taken out personal loans to help the party.
Mr Sheridan added: "There is no prospect of the SSP as a political party collapsing."
The SSP's financial struggle comes after the party, which has six MSPs, took on several high-profile political campaigns on issues ranging from the council tax to free school meals.
Each MSP gives half of their salary to the party and the SSP also gets £34,043 a year in "short money" - public cash allocated to opposition parties to enable them to carry out their parliamentary duties.
But as well as the boost to the number of its MSPs, the party has also taken on new commitments, and has recently moved into a new headquarters in Kinning Park, Glasgow.
Mr Sheridan said: "Politically we are stronger than ever, but financially we are suffering from overstretching ourselves in relation to these various campaigns.
"The basic figures are that our expenditure far exceeds our income, even though our income is very good for a small political party.
"We campaign as though we were in the Premier League when in reality we are only in the First Division."
Mr Sheridan, who is appealing to supporters to rally round, added: "Politically, we are now going to have to adopt the Martin Luther King principle - being judged not in times of tranquillity but in times of adversity."
The Socialists said their ability to act as a party was not in danger
A party spokesman added that, while the £200,000 figure was accurate, it needed to be examined in more detail.
He added: "That figure includes the mortgage for our national office, which is also an asset. Your average family doesn't go around saying it is 'x amount' in debt just because it owns a house.
"The figure is accurate in the strictest sense of the word, but can also be misleading when taken at face value.
"In no way will this affect our ability to cope as a national Scottish political party or fight the next general election."