On Monday, Nigeria's National Bureau of Statistics said the inflation rate had risen for the sixth consecutive month to 13.7 percent in April, up from 12.8 percent in March.
Nigeria depends on oil sales for 70 percent of government revenue and the global plunge in oil prices has weakened the naira currency and made foreign exchange scarce.
To make matters worse, junior oil minister Emmanuel Kachikwu said domestic production had fallen from 2.2 million barrels per day because of renewed militant attacks on pipelines and facilities.
"We are basically producing about 1.4 million barrels (per day)," he told parliament in a presentation to explain the petrol price rises.
- Subsidy system -
Kachikwu, who also heads Nigeria's state-run oil firm, last week announced the petrol price rise and deregulated the fuel import market to try to end shortages caused by the lack of forex.
Black market exchange rates are running at about 350 naira to the US dollar but the government has refused to change the official rate of 197-199.
As a result, fuel importers have been unable to source forex at the official market rate to buy supplies, causing pumps to run dry and long queues at filling stations.
Wranglings over subsidy payments between importers and the government have previously led suppliers to withhold deliveries in a system widely criticised as open to abuse.
OPEC-member Nigeria depends on fuel imports because of a lack of domestic refining capacity.
The government has kept prices at the pump low and paid the difference to importers but with overall oil revenue squeezed it can no longer afford to subsidise at 86.50 naira per litre.
Because of the lack of fuel, motorists have been paying upwards of 145 naira per litre for months.
Kachikwu told parliament the price rise was "absolutely essential" to kick-start growth, improve investor confidence and even for Nigeria "to survive as a nation".
- Economic 'tailspin' -
A previous attempt to end fuel subsidies in January 2012 saw petrol prices more than double but the government was forced to partially reinstate them after widespread protests.
But there were indications the unions may have misjudged the public mood this time around.
"(The NLC) should realise that Nigeria is already in a tailspin and cannot afford any strike that will worsen the nation's economic woes at this time," said Lagos stockbroker Sola Oni.
"Besides, the new price (of petrol) will end the fraudulent subsidy regime that has only enriched a few Nigerians," added Oni, from Sofunix Investments and Communications.
Public affairs commentator Quincy Durodola also questioned the timing of the union threat.
"NLC was quiet when their members in IPMAN (Independent Petroleum Marketers Association of Nigeria) collected subsidies and still sold above the subsidised rates," he said.
"It never saw anything wrong with that."
Meanwhile, the head of NUPENGASSAN, which brings together the two top unions for the oil and gas sector, said they did not support strike action and approved of the government's actions.
"We are in support of the deregulation," NUPENGASSAN Chairman Achese Igwe told AFP, adding that the union was "not part of the strike action".
"As it is today, the oil price is down. We need to raise funds. We need to sustain our economy. We need to create infrastructure on the ground, he said.