Article: Callaghan had been widely expected to call a general election in the autumn of 1978 when most opinion polls showed Labour to have a narrow lead. However he decided to extend his wage restraint policy for another year hoping that the economy would be in a better shape for a 1979 election. But during the winter of 1978–79 there were widespread strikes among lorry drivers, railway workers, car workers and local government and hospital workers in favour of higher pay-rises that caused significant disruption to everyday life. These events came to be dubbed the "Winter of Discontent".

Question: In what year was Labour shown to have a slight lead?
1978