PARIS (Reuters) -Labour union strikes in France over the government’s planned pensions overhaul will cause heavy disruption to public transport on Tuesday, the transport minister and several public transport authorities said on Sunday. Unions have called for a nationwide day of strikes and demonstrations and hope to repeat the large turnout seen on the first major protest on Jan. 19, when more than a million people marched against the reform. Strikes that day also halted trains, blocked refineries and curbed power generation. “It will be a difficult, very difficult day for public transport… …