Train drivers operating on key routes through Oxfordshire are set to ballot for strike action.

Union leaders representing about 900 drivers working for First Great Western (FGW), which runs services from Banbury and Bicester to Oxford and London Paddington, have given notice of the move to bosses after a dispute over sick leave escalated.

FGW has introduced a ‘managing for attendance’ policy designed to identifty anyone who has had an extended period of sick leave and ask them for an explanation in a bid to weed out shirkers.

But drivers fear those who are genuinely ill are being targeted, prompting safety concerns.

Aslef district organiser Stan Moran said: “Human resources managers have come down on people who have been certified sick by a doctor and brought them in for an interview. But how do you overule a doctor?

“They are frightening people to get them back into work but train drivers have a responsible job and there is a major safety factor involved. You don’t want someone driving a train if they are ill.

“But we are in talks and hopefully we can avert this. There is always a way forward.”

The union has also pledged to withdraw an arrangement allowing drivers to work on their rest days by the end of this month.

FGW spokesman Ellie Banks said: We spoke with ASLEF on Wednesday and are working closely with them to resolve this matter. Our priority is to prevent any impact on our customers."

She added: "We would never expect a driver to drive one of our trains if they were feeling unwell, and we have relief drivers in place to cover."