Nigerian leader in crisis talks on strikes Goodluck Jonathan, the Nigerian president, was in crisis talks with union leaders on Thursday night in an effort to end a violent nationwide strike over his government's decision to withdraw longstanding fuel subsidies. The meeting with leaders of the country's two biggest umbrella unions, the Nigeria Labour Congress and the Trade Union Congress, came after the country's biggest oil union, Pengassan, announced it would start shutting down oil production on Sunday. The move by Pengassan increased the pressure on the government, which depends on oil sales for more than 80 per cent of its revenue. Despite four days of mass action that have paralysed the country, Mr Jonathan has so far refused to reinstate the subsidy, whose removal on January 1 caused petrol prices to jump 120 per cent. Pengassan shall be forced to go ahead and apply the bitter option of ordering the systematic shutting down of oil and gas production with effect from ... 00.00 hours of Sunday January 15 if the federal government of Nigeria fails to yield to the popular agitation of Nigerians on [the] unacceptable approach to fuel subsidy removal," the oil union said in a statement. A smaller oil workers" union, Nupeng, is already on strike and has withdrawn its members from oil rigs. So far crude production has been unaffected, since many processes are automated and facilities well guarded. It is also unclear whether Pengassan workers would be able to stop output from Nigeria's offshore wells. Nonetheless, any significant reduction in output will hit an already struggling economy. Nigeria is Africa's largest oil producer, with an output of more than 2m barrels a day of premium low-sulphur crude, sent mainly to the US, India and Brazil. Any disruption would help to drive prices higher at a time when energe costs are already expensive due to growing frears about the building confrontation between western countries and Iran. Oil traders said, however, that they were more concern about the threat of attacks to pipelines and oil terminal than to the effect of the strike. Traditionally, strike-related outages had been short in Nigeria. Fears over Iran pushed benchmark Brent oil prices above $113 a barrel on Thursday. The strike has caused major disruptions to the economy. Lamido Sanusi, the central bank governor, told Reuters that the strike was costing the country around 100bn naira ($617m) a day and that the removal of the subsidies, which has seen petrol prices double, would cause inflation to rise to 14-15 per cent by the middle of this year, up from 10.5 per cent currently. The strikes have widespread support in Nigeria and have tapped into longstanding grievances over graft and government waste. Tens of thousands of people have attended nationwide rallies daily since the protests began on Monday, with organisers using social networking sites to rally support. Banks, shops and schools remain shut, although small vendors and hawkers are still operating. Domestic flights are on hold and youths armed with sticks and rocks have prevented motorists from moving freely in cities such as Lagos. Ports have also been affected. Until now the unions have insisted that the government reinstate the full subsidy, which allowed Nigerians to buy imported petrol at 65 naira ($0.40). But Elijah Okougboh, general secretary of the Nupeng oil union, told the Financial Times that there was room for compromise. "We must negotiate, and that does not just mean going back to 65 naira," he said. If anything happens to the oil and gas industry it will destroy Nigeria. The government spent more than $8bn on the fuel subsidy last year, which it said was unsustainable. Nigeria has to import most of its petrol dues to its rundown domestic refineries. Additional reporting by Javier Blas in London