LISBON, Portugal (AP) — Portugal is rationing gas as tanker truck drivers begin an open-ended strike over pay.

The government has set a limit of 25 liters (6.6 gallons) for customers at gas stations until further notice.

Some truckers in other sectors of the economy have also joined the walkout that started today. Anticipating gas and fresh food shortages, the center-left Socialist government, which faces a general election in October, is forcing the truckers to provide a minimum volume of supplies.