Referring to the country's drastic deficit-cutting budgetary plan, Ms Panaritis said: "That's why we're moving on as fast as possible, to be able to not get into that situation."
The MP's admission came after the prime minister George Papandreou announced a new revenue-raising property tax.
The EU's economic affairs commissioner, Olli Rehn, said the measure went "a long way" towards meeting the country's targets.
Earlier, Greece's deputy finance minister Filippos Sachinidis stated the country had funds to operate until next month.
There is a possiblity of running out of cash, especially if we don't get the suggested programme tranches
Elena Panaritis, Greek MP and Adviser to the Prime Minister
Data from the Finance Ministry showed the budget deficit had widened by 22% in the year to August to 18.1bn euros.
Ms Panaritis said the country's economic crisis was a "structural" one, rather than a liquidity one.
"The structural reforms take, unfortunately, a longer time than the actual fiscal reforms, which are the measures we've taken for the past year."
She stressed, however, that Greece had chosen to stay in the euro and that was why it was making such drastic cuts.
"We do need to be a little more patient about our returns and our tangible results."

Sky News