"It is going to be a general strike. We will shut down the economy," Adams Oshiomhole, president of the Nigerian Labour Congress, said on Wednesday after the umbrella organisation of unions met for more than six hours to decide a course of action.
Oshiomhole said the date and duration of the strike would be decided in consultation with civil society groups at meetings that would be held between Friday and Monday.
Asked how the strike would affect oil production in the OPEC member nation, he said: "It will be all-encompassing."
Blue collar oil workers' union NUPENG said last week it would not halt crude exports if it joined a general strike, because that could lead to the collapse of democracy in
Nigeria. No one from NUPENG was immediately available to comment after the NLC statement.
Oil exports have not been affected by a general strike since 1994, though a string of recent strikes over fuel price increases have paralysed the rest of the economy for days.
Price hike deplored
"The increases as imposed are not sustainable. They are doing violence to our people, they are doing violence to the business community and they are doing violence to the poor," Oshiomhole told reporters after the meeting.
A strike would be a test of a new labour law adopted in March that tightens conditions for striking. The law demands that a strike be sanctioned by a majority of union members in a vote, and prohibits compelling workers to join.
Nigeria is the world's eighth-biggest exporter of crude oil, but most of its 140 million people live on less than $1 a day and its infrastructure is among the worst in Africa.
It does not have enough refining or power generating capacity to cover its energy needs and imports more than half its daily consumption of 30 million litres of fuel.
The price of fuel at the pump rose to 65 naira (50 cents) per litre last Friday. The state oil company said the increase was necessary because record high oil prices meant the cost of imports had shot up and it could no longer afford subsidies of more than $4 million a day.
But the high price of crude also means Nigeria has been receiving windfall revenues from its crude exports and unions say it is unacceptable to increase the costs at such a time.