PESHAWAR, Pakistan — When the delivery truck finally arrives, laborer Sher Nawaz joins about 400 Pakistanis scrambling to buy a sack of wheat flour.

He returns empty-handed.

“We were told there was a bumper crop of wheat this season, but look at us,” Mr. Nawaz, 45, says, his voice trembling with anger. He waited three hours in a crowd at a Peshawar bazaar, only to have the state-subsidized flour run out before he and 100 others got any.

While terror attacks have left hundreds dead, it is flour shortages and rising food prices that will be the most pressing issues in elections next month in this poor nation of 160 million people.

Food prices jumped by about 14% in 2007, on top of double-digit increases for the two previous years. Now Pakistanis wait in long lines at state-subsidized stores to buy flour for the flat bread usually eaten with every meal.

The government blames hoarding by unscrupulous suppliers and smuggling of local wheat to Afghanistan and India where it can fetch higher prices. It has set up an emergency food committee that sends millers enough wheat every day to feed about 120 million people, according to its chairman, Farooq Ahmed Khan. About 5,000 paramilitary forces now guard flour mills and escort supply trucks.

But many Pakistanis blame a controversial decision by the government in early 2007 to export a half-million tons of Pakistani wheat.

Supplies later ran short, and Pakistan was forced to import wheat from Australia and Russia at 70% higher prices. The decision led to accusations of incompetence and corruption against an administration that has taken pride in managing an economy targeted to grow 7% this year.

The crisis will hurt the prospects for the ruling party in February 18 parliamentary elections. It adds to voters’ gripes over steep rises in the price of cooking oil, rice, fruit, and vegetables, and frequent electricity outages.