FILE PHOTO: A construction worker walks through the Dangote Oil Refinery under construction in Ibeju Lekki district, on the outskirts of Lagos, Nigeria July 5, 2018. REUTERS/Akintunde Akinleye/File Photo

ABUJA (Reuters) - Nigeria’s two main oil unions have prepared their members for possible nationwide industrial action over a staffing dispute with Chevron, they said on Saturday.

Nigeria, an OPEC member, is Africa’s largest oil producer and crude sales make up around two-thirds of government revenues in West Africa’s largest economy. The dilapidated state of its refineries means the country imports most of its refined fuel.

The Petroleum and Natural Gas Senior Staff Association of Nigeria (PENGASSAN) and Nigeria Union of Petroleum and Natural Gas Workers (NUPENG) accused U.S. oil major Chevron of attempting to sack thousands of Nigerian workers in violation of their contracts.

“NUPENG and PENGASSAN will not hesitate to embark on nationwide industrial action on this matter and we have already placed our members on red alert should the management of Chevron remain recalcitrant or adamant to rescind its anti-labor decision,” the unions said in a joint statement.

NUPENG President William Akporeha told Reuters the industrial action referred to would be a nationwide strike by members of the unions, who cover a broad range of jobs across the country’s oil industry.

Chevron did not immediately respond to requests for comment.