John Leach, assistant general secretary of the RMT union, has called on rail bosses to “stand by” their staff.He spoke on Thursday morning, as strike action across the London Underground brought the capital's public transport service to a standstill."My message to TfL now will be to stand by your staff," Mr Leach said."Listen to your staff. Thousands of them are on strike today for the sixth time this year. They're losing lots of money... but don't they realise in management, there's a serious problem here?"