London commuters are facing more strike disruption after workers at a major rail operator voted to walk out.

Staff at Great Western Railway (GWR) have backed strike action in a dispute over flexible working arrangements, pay and pensions.

Members of the Transport Salaried Staffs Association (TSSA) working in areas including rostering, service delivery and performance strategy are involved in the row.

It has not yet set dates for strikes.

The strike announcement comes as London faces eight 24-hour strikes on the Tube in November, December, January and February.

The National Union of Rail, Maritime and Transport Workers (RMT) announced a new wave of walkouts in a row with Transport for London (TfL) over a voluntary four-day week for Tube drivers.

TSSA general secretary Maryam Eslamdoust said: “Strike action and action short of a strike, which will have a real impact on services at GWR, are now inevitable unless the company addresses these perfectly legitimate demands.

“It’s in no way reasonable for our members to suffer any financial hardship for doing shift work, which in itself runs the increased risk of physical and mental impairment.

“Likewise, for clerical grades, it’s simply not acceptable that they see their workloads increase without that reflecting both grading and pay.

“Our union only uses strike action as a last resort so the ball is very much in GWR’s court.

“We stand ready to get back around the table and talk at any time.”

The Standard has contacted GWR for comment.