Rail commuters travelling between Oxford and London say timetable changes introduced by First Great Western are inadequate.

More services to London have been added at Didcot Parkway. But Zahra Akkerhuys, a spokesman for OxRail Action, said the changes failed to address the "very real concerns" of Oxford commuters.

She added: "OxRail Action believes First Great Western is merely fiddling while Rome is burning. The changes are virtually insignificant. No changes have been announced for the 7.05am train, which continues to be a cramped Turbo.

"Also, there is still no fast train to London between 5.51am and 6.38am, making it hard for commuters to get to their desks before 8am."

Ms Akkerhuys added that the key change affecting Oxford passengers was that the 5.55am departure now leaves at 5.51am and is operated by two Adelante units, giving a 10-coach train, calling at Radley and Pangbourne, which slows the journey time to London Paddington to one hour, nine minutes.

Last December, the company infuriated passengers by cutting the number of fast morning peak trains from Oxford to the capital from six to three.

A month later, it introduced a revised timetable with an extra fast train at 7.33am and speeded up another service. In March, it provided more than 200 extra seats on the 7.33am service.

Adrian Booth, a spokesman for First Great Western, said: "We have been talking to OxRail Action Group for some time, and have explained that changes that they would like to see introduced are not straightforward. We explained to OxRail Action Group that there will be no significant changes made in May. They have understood this for weeks."