LISBON (Reuters) - Energy shortages in Portugal sharpened on Wednesday as a strike by fuel-tanker drivers entered its third day in the worst industrial unrest of the Socialist government’s four-year rule.

A placard reading "Diesel sold out" is seen at a gas station in Porto, Portugal April 17, 2019. REUTERS/Rafael Marchante

Panicked motorists formed long lines at petrol stations, some crossing into Spain to refuel, while at airports reserves reached critically low levels in the run-up to the tourism-dependent economy’s busy Easter season.

Prime Minister Antonio Costa’s government on Tuesday ordered striking drivers to supply essential services such as hospitals and airports, and to provide a minimum amount to fuel stations - but the decree did not seem to be fully heeded.

“The government will do everything to overcome the conflict,” Costa, whom the opposition accuses of mishandling the crisis, told parliament.

Crowd-sourced emergency services platform VOST Portugal said that more than 2,000 petrol stations were running on reduced fuel supplies - up from around 200 on Tuesday.

The drivers’ union said on Wednesday the strike would continue until the government moves to resolve workers’ demands for better pay and conditions from employers.

“This political war will only harm people,” taxi driver Antonio Santos told Reuters in Lisbon. “It affects everyone. There are taxi drivers unable to work. I had to spend almost two hours at a petrol station to refuel.”

The strike follows a wave of disputes in a nation that had been lauded by European institutions as an economic model, implementing painful austerity measures after the global financial crisis a decade ago to underpin recovery.

Costa’s minority Socialist government, backed in parliament by the Left Bloc and the Communists, faces a general election in October this year. Though expected to win, the Socialists may struggle to win enough seats to form a majority.

WIDENING UNREST

Unrest is growing, as health and education workers also complain about low wages, threatening to undermine the government’s vote-winning reputation as good economic stewards.

Economist Filipe Garcia, of consultancy firm Informacao de Mercados Financeiros, said 90 percent of freight transport in Portugal was by road meaning a prolonged strike could have a major impact on an economy expected to grow 1.9 percent this year.

After at least one flight was called off on Tuesday, there were no reports of additional cancellations on Wednesday.

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Airport authority ANA said fuel supply had been resumed at airports in the capital Lisbon and Faro in the Algarve region - Portugal’s two biggest tourist hubs.

The airport in Porto, another tourist spot, was coping as fuel arrives through a pipeline, news agency Lusa said.

Under the government decree declaring a national energy crisis, drivers must supply fuel to 40 percent of gas stations in Portugal’s biggest cities Lisbon and Porto.

The union said workers will comply but not supply more.

However, Portugal’s Association of Oil Companies told Lusa that many gas stations were not being refueled despite the decree. The news agency reported that the government had 15 soldiers ready to drive fuel trucks if needed.

On Tuesday, before the government’s crisis talks with union and industry representatives, state agencies including the security forces chartered commercial fuel trucks to ensure supplies to Lisbon airport.

Costa said the government was determined to deliver essential fuel supplies across Portugal, not just to its biggest cities, Lisbon and Porto.