The Nigeria Labour Congress (NLC) and a coalition of civil society bodies have called on workers to launch an indefinite stoppage from 16 November in protest against rising fuel prices and President Olusegun Obasanjo's economic reforms.
Its leaders have warned their strike will disrupt key oil exports.
Campaigning is due to get off to a rowdy start on Wednesday when the strike coalition is to stage a street rally in Lagos which will be followed by similar protests around the country, said NLC mobilisation officer Denja Yacqub.
But first, union leaders went to court to see off a separate challenge from Shell, the country's biggest oil company, which was seeking an injunction to prevent its workers going on strike to oppose imminent job losses.
Shell's approach to the Federal High Court in Lagos was an attempt to add legal weight to its bid to force through an unpopular restructuring plan which is expected to lead to large-scale job losses in its Nigerian subsidiary.
But its own battle with the unions became drawn into the national struggle and labour leaders descended on the court house to denounce the firm's alleged strong-arm tactics.
Shell produces oil in Nigeria for
around $2 per barrel
"Shell does not have the muscle to control our people, even if it controls our political leaders," stormed NLC president Adams Oshiomhole, who on Sunday had dubbed the Anglo-Dutch major an "enemy of the Nigerian people".
"If you really want the government to listen to you, then the oil sector must be carried along in your struggle," he urged workers.
Oil revenues account for 95% of Nigeria's foreign earnings.
In court, Shell's lawyers argued that staff belonging to the two main oil unions, the National Union of Petroleum and Natural Gas workers (Nupeng) and the Petroleum and Natural Gas Senior Staff Association of Nigeria (Pengassan) had signed contracts pledging not to strike until all avenues of discussion with management had been used up.
But Pengassan president Brown Ogbeifun said that workers did not trust Shell not to cut jobs and that they reserved the right to strike not only over that but also in support of the NLC's broader nationwide conflict over fuel prices.
"If you really want the government to listen to you then the oil sector must be carried along in your struggle"
"If our members feel like joining the strike, we will," he said on Monday, after a hearing in which the judge had adjourned hearings until 18 November, two days after the general strike is due to begin.
Shell, which last week announced a 70% increase in worldwide third quarter profits, produces oil in Nigeria for around $2 a barrel.
The firm has begun a rationalisation to further cut costs and job losses are expected. Shell spokesmen were unavailable for comment.