A Nigerian court is expected to issue a ruling Friday on whether labor union leaders can legally call a strike to protest a new tax.

The issue before the appeals court is whether labor unions can call strikes on issues not directly related to working conditions.

The government brought the case to the court of appeals after a lower court ruled the strike could proceed. The appeals court issued an order on January 28 to suspend the strike as well as the gasoline tax until a decision in the case could be made.

Nigeria's largest labor union, the National Labor Congress, called for a nationwide strike in response to a new gasoline tax imposed early this year. The head of the National Labor Congress, Adams Oshiomole, is opposed to the tax because he says it has not been approved by parliament and is too great of a burden on poor Nigerians.

Nigerian President Olusegun Obasanjo says the tax is necessary to pay for highway maintenance.

The price of gasoline has been on the rise since last year as part of the government's efforts to reform its large oil sector, which includes ending oil subsidies.

The new tax is the equivalent of about one U.S. cent per liter of gasoline. Although Nigeria is one of the world's top-10 oil producers, the majority of its people survive on less than $1 a day.

Many impoverished Nigerians, as well as human rights activists and union leaders, believe access to cheap gasoline should be guaranteed to all Nigerians.

The appeals court was originally expected to rule on the legality of the new tax and the legality of the strike. But court officials say the decision on Friday is only expected to rule on the matter of the possible strike.