Tube drivers in 24-hour strike over 'heavy-handed' bosses
Tube drivers on two London Underground lines have begun a 24-hour strike.
Members of the Rail, Maritime and Transport (RMT) union working on the Hammersmith & City and Circle lines walked out at 21:30 BST.
The strike comes amid claims that industrial relations have broken down.
Transport for London (TfL) had warned there would be no Hammersmith & City line service and a limited service on the Circle line from around 21:00 BST and throughout Friday.
The RMT has accused TfL managers of being "heavy handed", including putting staff toilet breaks on a stopwatch and a "flagrant disregard" for agreed policies and procedures.
RMT general secretary Mick Cash said: "This dispute is about the basic issues of protecting working conditions of our members and defending agreements from attempts to drive a coach and horses through them."
Operations director Steve White said London Underground understands drivers need to take a break but said "a minority are taking breaks of an hour or more and calling them toilet breaks," which had a direct impact on customers.
He said it as "absolutely not true" toilet breaks were being timed, but said management was offering help through an occupational health team if a driver has issues requiring longer breaks.
TfL has advised commuters to check its website for travel information, but said all other TfL services would be operating as usual.