Drivers on a busy London Underground line are planning to hold two 24-hour strikes in a row over working conditions and claims of bullying, threatening disruption after the Easter break.

Staff morale on a Tube line faces constant pressure from frequent breakdowns

Members of the Rail Maritime and Transport Union and train drivers’ union Aslef on the Jubilee line are set to walk out next Tuesday and again on May 2.

The drivers voted overwhelmingly in favour of industrial action, claiming there had been bullying of staff and an “appalling decline” in the standard of working conditions, which the unions said have led to a breakdown in industrial relations.

RMT general secretary Bob Crow said: “There has been a cynical attempt to trivialise the issues at the heart of this dispute, but the fact is they amount to a systematic undermining of working conditions and staff morale on a Tube line that faces constant pressure from frequent breakdowns and failures, and where drivers are in the front line of trying to maintain both an effective service and passenger safety.

“Their reward has been attack after attack on working conditions and on both individuals and the drivers as a group of staff.”

Talks will be held at the conciliation service Acas to try to avert the strikes.

An Acas spokesman said yesterday: “Productive talks were held today at Acas between London Underground, RMT and Aslef.

“The parties have adjourned for the evening to consider their positions.”