The Rail, Maritime and Transport union has warned Transport for London to stop propagating "dangerous lies" about the amount of tube services running during today's strike, suggesting such misinformation could cause a crush.
The Union began a 24-hour strike at 6pm last night, in a row over ticket office closures.
Several stations, particularly in central London, are closed and Transport for London says eight out of 11 lines are running a limited service.
This morning, Clapham Junction station had to be evacuated due to over-crowding and the RMT believes similar problems could arise over the rest of the day if TfL doesn't start giving accurate information about the extent of the disruption.
The general secretary of the RMT Union Mick Cash said: "It does no one any favours for TfL to openly lie about how many tube services are running. It just piles more people into stations that are already dangerously over-crowded and ramps up the risk of a major crushing incident.
"TfL should stop peddling their fantasy world of services that are operating when the truth is that London is on an almost total shutdown.
"They should cut out this lethal nonsense and get their top London Underground bosses back round the negotiating table with a serious set of proposals to settle this dispute."