He added reserves of industrial-grade fuel have dwindled to 400,000 litres since Israel halted fuel deliveries after Palestinian fighters attacked the territory's main fuel terminal on Thursday.
The Israeli army's co-ordinating office and the private Israeli company charged with supplying fuel to Gaza declined to comment on the matter.
Rafiq Maleha, director of the Gaza Power Station, told Al Jazeera that fuel has not entered Gaza since last Thursday.
The Gisha Legal Centre, an Israeli human rights group, on Tuesday wrote to the Israeli attorney general warning that the cuts "violate the state's commitment to the supreme court to permit a minimum amount of fuel to enter Gaza".
They also warned that once the power plant shuts down, the impoverished territory would face power cuts lasting eight-to-16 hours a day.