France has begun importing electricity as the wave of strikes against pension reforms takes hold of energy supplies. The news emerged as President Nicolas Sarkozy warned that the economy and jobs could be hit if the disruption did not end quickly. Yesterday, in one hour, 5,990 megawatts were imported, equivalent to the output of six nuclear reactors.At least 12 of France's 58 reactors are shut for maintenance but the unions say production has been cut at four others. France's other energy supplies have already been severely disrupted by industrial action which has left all the country's 12 oilrefineries blockaded for more than a week and a quarter of its petrol stations empty. MPs were told yesterday that 3,190 had run dry.Meanwhile, workers and unions protesting against the pensions reforms have blocked access to Marselle airport in the south of the country. A union representative said all roads to the terminal have been blocked, but the airport authorities said some vehicles were getting through and that no flights have been cancelled so far.