TORONTO, April 30 (Reuters) - North American graphite miners are lobbying the US government to impose a 25% tariff on three graphite products sourced from China in order to counter Beijing's monopoly on a key material used in automobile batteries.If successful, the move will pit the miners against their main customers- the original equipment manufacturers (OEMs) and add to tensions with China, which controls the majority of the critical metals used in the world's electric vehicles and other motors.The U.S. government is set to decide in May whether to bring graphite into the list of minerals that attract the higher Section 301 tariff.The Section 301 tariff was introduced by former U.S. President Donald Trump after his administration found China's "acts, policies and practices related to technology transfer, intellectual property, and innovation are unreasonable and discriminatory". Many other parts used in electric vehicles are also subjected to additional levies.Graphite miners lobby US govt to impose levy on China-sourced EV material.