A six-day strike by drivers on Southern Railway next week has been cut to three days, but there is a likelihood of further action in the bitter dispute over driver-only trains.

Members of Aslef were due to walk out from Monday, which would have halted services for the entire week.

The union announced that strikes will now be held on January 10, 11 and 13 but not on other days next week.

General secretary Mick Whelan said the move did not mean the union was rolling back and warned of further strikes.