London Midland trains has been accused of "putting people’s jobs and livelihoods at risk" after a passenger survey found more than a third of respondents had been in trouble at work due to delays.
More than 300 people took part in an online survey set up by disgruntled passengers from south west Hertfordshire last month.
The findings have prompted users from the area to call for London Midland to publish performance statistics so passengers can see if the service is improving.
Kings Langley resident Joanne Ashford, 29, one of the passengers behind the survey, said: "In a time of austerity, London Midland is putting people’s jobs and livelihoods at risk, and hindering national productivity.
"London Midland made repeated promises to improve their services by 9th December 2012, after Prime Minister David Cameron said the company was on "a warning list" because of its unacceptable service.
"However, our research showed that only 6% of respondents had experienced no delays to their journeys since 9th December 2012."
The survey showed 39 per cent of respondents said their boss had spoken to them about their timekeeping as a result of London Midland delays.
It also revealed that 79 per cent of passengers surveyed felt they did not get value for money for their season ticket and 91 per cent had experienced delays since December 9 when London Midland introduced a new timetable and staffing arrangements.
Miss Ashford added: "As paying passengers, we want to see the performance statistics London Midland is submitting to the government as a result of being on the ‘warning list’, as well as a clear action plan on how they will improve the service.
"We have put up with a poor quality of service for long enough, and now London Midland must be held accountable.
"If they cannot significantly improve the service by Parliamentary Easter recess, we will be lobbying for a franchise review."
London Midland is yet to respond to the survey’s findings.