Drivers are queuing in Portugal as 40% of the country’s petrol stations have run out of fuel due to an ongoing tanker drivers’ strike.

The Portuguese government on Wednesday implemented emergency measures to guarantee fuel supply for ambulances, airports, fire trucks, the military, and other critical services. Some flights are being diverted to Spain to refuel, while the military is in the process of escorting convoys of fuel trucks.

The Socialist government backed by the far-left is expected to declare an “energy crisis” on Tuesday, forcing strikers to maintain 100% fuel supply to hospitals and a minimum of 40% to gas stations in Lisbon and Porto.

On Wednesday, Prime Minister António Costa sought to mediate between the National Union of Dangerous Goods Drivers and employers. Workers are demanding a pay rise of 40%, from €700 to €1,200 a month. The suppliers refuse to negotiate while the strike is underway, but have said that minimum service requirements set by the government will continue.