Talks are being held in a bid to avoid more strikes on London Underground in a dispute over jobs and ticket office closures.

Officials from the Rail, Maritime and Transport (RMT) union and the Transport Salaried Staffs Association (TSSA) met LU chiefs under the chairmanship of the conciliation service Acas.

Members of the two unions staged a 24-hour strike last week which crippled Tube services, causing travel chaos.

The unions said a programme of hundreds of job cuts agreed by former London mayor Boris Johnson has gone too far and is affecting safety.

LU has agreed to new jobs but not enough to satisfy the unions.

The RMT has warned of further industrial action after February 6 if the row is not resolved.

RMT general secretary Mick Cash said: “RMT members on the London Underground stations see day in and day out the toxic impact of the job cuts programme and they are reporting back it is horrific.

“It has now also been shown at management level there is agreement with the union the cuts have been a disastrous mistake and the staff need to be put back on the stations.

“We now need a move away from the piecemeal and incremental approach to tackling this crisis and for LU to come forward with a serious package of proposals.”

London Underground chief operating officer Steve Griffiths said he was looking forward to the resumed talks in order to make progress towards resolving the dispute.

TSSA general secretary Manuel Cortes said: “We are hoping to make progress towards a resolution which ensures our Tube is both safe and adequately staffed.”