The pressure on the health system caused by the nurses' strike is steadily increasing, and the Finance Ministry is preparing to seek back-to-work orders if the situation continues to worsen and a deal remains elusive.

The parties resumed negotiations Wednesday evening, but the talks failed to produce results.

The treasury claims that in a deal signed with the nurses union in March, the union promised not to strike until the beginning of 2013 - a provision that would justify seeking a back-to-work order. But the nurses claim the treasury violated that agreement by refusing to begin negotiations on a new wage deal in September.

The strike, which began on Monday, has already led to the postponement of most non-urgent operations in hospitals, as well as long lines at hospital outpatient clinics, the virtual closure of nurses' clinics at the Clalit health maintenance organization and a cessation of most vaccinations at well-baby clinics. Health professionals estimate that more than 5,000 operations have been postponed.

The strike affects all hospitals owned by either the government or Clalit, as well as two private hospitals in Jerusalem, Hadassah and Shaare Zedek. Altogether, some 28,000 nurses are on strike.

Currently, the average occupancy rate in the country's hospitals is about 94 percent, which is normal for this time of year. But pediatric wards are unusually overcrowded, with a nationwide occupancy rate of 110 percent and rates as high as 153 percent at Hadassah Ein Karem and Sheba Medical Center in Tel Hashomer and 123 percent at Hillel Yaffeh in Hadera. Some internal medicine wards are also extremely overcrowded, with occupancy rates reaching 150 percent at Hadassah Ein Karem, 136 percent at Haemek in Afula and 131 percent at Hillel Yaffeh. These overcrowded wards, which in some cases have been forced to stash patients in the corridors, are suffering particularly from the nurses' strike, which has led to a sharply reduced presence of nurses on the ward.

On Wednesday morning, 300 nurses demonstrated opposite Beilinson Hospital in Petah Tikva, bearing signs with slogans such as "Enough with the exploitation!"

"What's happening now is like a ticking bomb," said the head of the nurses union, Ilana Cohen. "Just remember what happened with the firefighting services: They kept warning [that a disaster was waiting to happen], and no one listened."

The treasury argues that the nurses are demanding a double-digit wage increase, which simply isn't possible in the run-up to January's election: On orders from the attorney general, the government is supposed to avoid taking far-reaching financial steps during campaign season unless they are unavoidable.