LISBON, Portugal (AP) — Striking tanker truck drivers in Portugal are defying a government order and refusing to make limited deliveries to gas stations.

The move Wednesday stoked fears that gas stations will soon run dry and deepened political tension less than two months before a general election.

Portugal is already rationing gas three days after the walkout began, and the center-left Socialist government on Tuesday enacted a rarely-used law forcing the truckers to provide a minimum volume of supplies aimed at keeping the country running.

Authorities hoped to minimize disruptions by demanding that truckers maintain 75% of normal gas deliveries for public transport systems and 50% to gas stations.

Failure to comply with the government order is punishable with up to two years in prison.

Soldiers and police have also made gas deliveries.